HARVARD UNIVERSITY

Library of the

Museum of

Comparative Zoology

o^

H E

MCZ
LIBRARY

MAR 1 U 1998

HA.'7\/ARQ
UlNiiVt:R:3lTY

GREAT BASIN

NATURALIST

VOLUME 58 NO 1 — JANUARY 1998

BRIGHAM YOUNG UNIVERSITY

GREAT BASIN NATURALIST

http://www.lib.byu.edu/~nms/

Editor

Richard W. Baumann

290 MLBM

PO Box 20200

Brigham Young University

Provo, UT 84602-0200

801-378-5053

FAX 801-378-3733

Assistant Editor

Nathan M. Smith

190 MLBM

PO Box 26879

Brigham Young University

Provo, UT 84602-6879 '

801-378-6688

E-mail: NMS@HBLL1.BYU.EDU

Associate Editors

Bruce D. Eshelman

Department of Biological Sciences, University of

Wisconsin-Whitewater, Whitewater, WI 53190

Jeffrey J. Johansen

Department of Biology, John Carroll University

University Heights, OH 44118

Boris C. Kondratieff

Department of Entomology, Colorado State

University, Fort Collins, CO 80523

Paul C. Marsh

Center for Environmental Studies, Arizona

State University, Tempe, AZ 85287

Stanley D. Smith
Department of Biology
University of Nevada-Las Vegas
Las Vegas, NV 89154-4004

Paul T. Tueller

Department of Environmental Resource Sciences
University of Nevada-Reno, 1000 Valley Road
Reno, NV 89512

Robert C. Whitmore

Division of Forestry, Box 6125, West Virginia

University, Morgantown, WV 26506-6125

Editorial Board. Jerran T. Flinders, Chairman, Botany and Range Science; Duke S. Rogers, Zoolog>';
Wilford M. Hess, Botany and Range Science; Richard R. Tolman, Zoolog\'. All are at Brigham Young
University. Ex Officio Editorial Board members include Steven L. Taylor, College of Biolog\' and Agriculture;
H. Duane Smith, Director, Monte L. Bean Life Science Museum; Richard W Baumann, Editor, Great Bas/'/i
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Editorial Production Staff

JoAnne Abel Teelinie;il Lditor

Copyright © 1998 by lirinliain VoiiiiK l'iii\frsity
OITicial piil)lkati<)ii date: .?() January 1998

ISSN 0017-3614
1-98 750 24893

The Great Basin Naturalist

Pi i5i.isiii;i) vi Ph()\(), Utah, by
Bkicii \\i Vol \(. r\i\ i.Hsni

ISSN ()()17-3(S14

N'oiAMi; 58 31 January 1998 No. 1

(".rcat Basin Naturalist 58(1). © 199S. pp. l-II

TAXONOMY OF SPHAEROMERIA, ARTEMISIA, AND

TANACETUM (COMPOSITAE, ANTHEMIDEAE) BASED

ON RANDOMLY AMPLIFIED POLYMORPHIC DNA (RAPD)

.,-2

E. Durant McArtliur', liencc \'an Burcn-'l Stewart C. Sanderson', and Kiinl)all T. Harper

Abstract. — Relationships within, lietween. and among the Antlieniideae geTiera Spliacroineria, Artemisia, and
ruiHicetum were investijiated nsing 2.38 randoniK amplified poKnioiphic DNA (Il^PD) markers obtained from twenty
lO-mer primers amplified on genomie DNA. Forty-one populations from 16 taxa (1.5 speeies) were studied. Jaeeard's
eoeffieient of similarit\ and UPCMA clustering analysis were used to construct phenograms. T tests were used to make
comparisons het\vcen samples at various systematic levels. DNA markers were 757c similar for conspecific populations.
Si.xteen Sphaeromeria populations (5 species) showed an average interspecific similarity of 21%. Interspecific similaritx
among 23 Artemisia populations (8 species widi 2 subspecies of A. tridentata included) averaged 27%. Two Tanacetum
species (1 population each) were 89% similar. The high similarit\' of the Tanacetum species was in the range of obsened
\alues for conspecific populations; indeed those 2 species {T. vulgare and T. boreale) have been considered conspecific
b\- some authors. The 3 subgenera of Artemisia studied {Artemisia, Dracunculus, and Tridentatae) formed separate
groups. In comparisons among the genera, Sphaeromeria was 18% similar to Artemisia (more similar to subgenus Tri-
dentatae than the other Artemisia subgenera); intergeneric comparisons of Sphaeromeria and Artemisia and Artemisia
and Tanacetum each were found to be 7% similar to each other Thus, based on DNA markers, Sphaeromeria is more
similar to Artemisia than it is to Tanacetum, which supports previously established morphological distinctions.
Sphaeromeria potentilloides nia\ l)e misplaced in tlie genus Sphaeromeria based on DNA marker results. It is likeK' th;it
North .\merican Anthemideae are circuni])()real deri\ati\es of ancestral Eurasian stock and that Spltaeromcrid is deri\i-d
horn an ArtemisiaAikf ancestor

Key words: .Sphaeromeria, Artemisia, Tanacetum, .A»//i()/i»/(«e, R-AFD, taxoucnntj.

Two decade.s ago Holmgren et al. (1976) duced the ta.xon to subgeneric status (section

published an intriguing article, '^Sphacrome- Sphaeromeria) in the genus Tanaeetwn. Sphae-

ria, a genus closer to Artemisia than to Tanace- romeria, endemic to western North America

fiim (Asteraceae: Anthemideae)." In their article (Holmgren et al. 1976, McArthur et al. 1989,

Holmgren et al. (1976) returned Sphaeromeria Croncjuist 1994), consists of 9 species, 8 of

to the generic rank first proposed In Nuttall them rare. Several authors have noted that an

(1841). T()rre\- and Crav (1843), however, re- understanding of relationships between and

'Slirub Sciences Laborator\, Rock\ Mountain Research Station, Forest Service. United States Department of .•\griciiltiire, 135 N. .5(X) E., Provo, UT 84606.
^Department of Botan\ and Ranjje Science, Brighani Young Universitv-, Provo. UT 84602.
•'Present address; Department of Life Science, Utah Valley State College. Orem, UT 84058.

Great Basin Naturalist

[Volume 58

within the genera Artcinisia and Tanacetum
would he enlianced h\ new information on the
distribution and ph\'logeny of that portion of
the tribe Anthemideae (Hall and Clements
1923, Holmgren et al. 1976, McArthiu" 1979,
MeArthur et al. 1989).

Artemisia is the largest genus of Anthem-
ideae, consisting of 250 or more species divided
into 4 subgenera. It is distributed mostly in
temperate portions of the northern hemisphere
but also in South America and South .\frica
(Willis 1973, Bailey Hortorium Staff 1976,
Greger 1978, MeArthur 1979, MeArthur et al.
1981, Ling 1995a). Tanaceiwii consists of some
50 species with a Eurasian distribution except
for the T. bipinnatinn complex, which is cir-
cumpolar (Willis 1973, Bailey Hortorium Staff
1976, MeArthur 1979, K> hos'and Raxen 1982).
Here, we address relationships among the
genera Sphaeromeria, Arte^nisia, and Tanace-
tum using genomic DNA markers from repre-
sentati\'e species from each genus. We also re-
view species and generic distributions.

Randomly amplified polymorphic DNA
(RAPD) analysis has been shown to be useful
in studying plant population biology, in pre-
paring genetic maps, and in classifying plants
(Williams et al. 1990, 1993, Dawson et al. 1993,
Russell et al. 1993, Williams and St. Clair
1993, Santos et al. 1994, Van Buren et al. 1994,
Bradshaw ct al. 1995, Gang and Weber 1995,
Yeh ct al. 1995, Bonnin et al. 1996, Karp et al.
1996, Lanner et al. 1996, Lin and Ritland 1996,
Mudge et al. 1996, Smith et al. 1996, Stock-
inger et al. 1996). Whereas this paper examines
similarity among related Anthemideae genera,
a companion paper (MeArthur et al. 1998) uses
RAPD technology to examine hybridization
and poK'ploicK within the subgenus Triden-
tatae of 1 of those genera {Artcinisia). Our use
of RAPD data to compare genera is novel but
is, we believe, a natural extension of the man>'
studies that have made population and species
comparisons.

VLVIKHIALS Am) Mf.tiiods

riant Materials

We identified and selected for study species
representing moiphological variation and geo-
graphical spread of tlu' 3 genera of concern.
C^ollecting sites lor repi"cscntati\r populations
were determined lor S})li(icr<iincri(i and Arlciiii-
sia (Table 1), and rcprcsciitatixcs lor rdiuiccliiin

were grown in our greenhouse hom seed ob-
tained Iroiu European colleagues (Table 1). We
collected samples between Ma)' and August
1995, in most cases 3 populations (range 1-4)
for each ta.xon. By combining tissue (\'oung
leaves) from 30 health) but otherwise ran-
doml) chosen individuals of each population,
we ol)tained a "bulked sample" for each popu-
lation. Leaves were collected in nylon bags,
inunersed immediatel) in li(iuid nitrogen, and
transported to the laboratory w here the)' were
stored at ultra-cold temperatures (-80°C) until
DNA was extracted. Herbarium \'oucher spec-
imens are deposited in the Shrub Sciences
Laboratory (SSLP) or the Brighani Young Uni-
versity (BRY) herbaria. Following methods of
MeArthur and Sanderson (1985), we made a
chromosoiue count from root tips of S))hae-
romeria divcrsijoha to extend the c)tological
knowledge base in Sphaeromeria (several but
not all Sphaeromeria species are cytologicalK
known; Powell et al. 1974, Sanderson et al.
1984, MeArthur et al. 1989).

DNA Extraction and Amplification

Bulked leaf samples were thorougliK mixed
and a sample weighing 0.3-0.5 g from each
population was used for DNA extraction.
Extraction procedures generally followed Bult
et al. (1992). This protocol resulted in high
)ields of genomic DNA ranging from approxi-
matel) 100 /xg/ml to nearl) 400 /xg/ml. DNA
concentration was estimated using a Beckman
DU 640 mass spectrophotometer (Beckman In-
struments, Inc., Fullerton, CA). The extracted
DNA was diluted with TE (1 M Tris and 0.5
M EDTA, pi I 8.0) to achieve a final concen-
tration of approximately 2.5 ng/)Ltl.

Amplification of genomic DN.\ was accom-
plished following procedures reported b)
Williams et al. (1990). Amplification reactions
with a final xolume of 15 fil contained the fol-
lowing: 5-10 ng DNA, 1.5 /aI lOX buffer, 100
p.\\ each of 4 deox) nuclc-oside triiihosphates
(cL'Vn^ (Km; cIGTH and d'lTP), 3.5 niM MgC:l2,
0.4 (x\\ primer (Operon Technologies, Inc.,
Alameda, GA), and 1.2 U Stolid Fragment (Per-
kin l']lmer-(>etus, NoiAvalk, CT). .\mplilication
was carried out using a Perkin ElnuM-C'etus
DNA 48-well thermal e)cler with the follow-
ing cycling regime: (1) 3-min initiation step at
92°Gi (2) 92''G for I min. 35°G for 1 min 45 sec,
72°G foi- 2 min, repeated for 45 c)cles; and (3)
72'(; for 7 nnii. Goutiol reactions eonsistcd ol

1998]

FL\PD (Ion iKiiu iioN lo Antiikmidi: \i-: Taxonomy

ti on 00 55
C <u C

O
, „ c/i ^

"2 ,«^ 3 c E

ti -r § jn s.„.^ 18 July 1995

— 009- .2 (N

CO "O 'JIJ "o <U i5

■^ o ^ g H -"H c

3

0, Kl 1) "" d)

OS

o

00 2 O T3

S ^ t. § =

C to t^ O —

boas '^ B ,^ c/D

o .2 T-!

" 'i j;! ^ O ^ ,N\, M6cS2427

W-. on 124

2 O t- '^'" .E "" "^ '"■>■ 1995

^.E ^ ■£ ^ §• ^ 1995 (also M&S 2041)

0 •§ i ^ C ^ 2 aCo.UX

O S ;^ ■" I— '

5 rt vI.SA'Miis.n.

C OD — X 52 S ", M.S.&Mii.S'.n.

^ 5P^ ;>; <" 2 ^ vl,S,&.Vlii 239.3

C •- c rt "^ "^ -^ M&S 2437

60-*^ g oa oj >. O s.n.. 8 June 1995

C IS >^ '^ ^ op VA-.n.,5Junel995

O 73

D. O D. f^ O — to .B-

^■^S-o^^E^

I 3 1> <u on

-'^2'^c^S^"" ^

Sl^Sit^^l-^ci).. I 73. Tooele Co., UT,

3 p S -5 175 ^ t9

'^ " - — •-" a. eq 3 ticj95

>Cc2-^'co. '^ " 't^ f^E 5.n., ISJulv 1995

^<2 :^^-5-5f^.E 1 "H. |=>S ??|-,

— ^>,e/5b5c:2,^ .E - 5(50^ rn(s)

|o^;^^^|'S X -i ^|S -b ,UT,H&Vs.n..

c ^ E ctC^-SS^Str

c ij .E ^ ^ J o 5 §

•s£— iur^on •:: o •t:^t:'c£<CL<i> «v.s.n., isjulv 1995

I^.^S^^-g "^^ ^ OJCQ&- <V.v.„.. 18 July 1995

'^ O :> ii <u ilv 1995

fc, C :S O 3 •" ^'^'^ population trom

o « 12 =5 "^

*" •— O i*- .— <_i )rtus Centralis Cultura

itas, Masarykiana 770

S^H-S'ga as g o.SicDH.... 2426

u —, cd h <u — -cwj-oc

. — o (u ;ermanv0613

Joanne Mudge, S= Stewart

Great Basin Naturalist

[Volume 58

witliin the genera i
would be enhanced 1
distribution and ph}
the tribe Anthemid
1923, Holmgren et
McArthur et al. 198f

Artemisia is the
ideae, consisting of 2
into 4 subgenera. I
temperate portions c
but also in South /
(Willis 1973, Baile
Greger 1978, McArt
1981, Ling 1995a). 7
50 species with a Ei
for the T. hipinnatu
cumpolar (Willis 19'
1976, McArthur 197
Here, we address
genera Sphaeromeri
turn using genomic J
sentativc species fro
view species and gei

Randomly ampl:
(RAPD) analysis has
in studying plant p(
paring genetic maps
(Williams et al. 1990,
Russell et al. 1993
1993, Santos et al. If,
Bradshaw et al. 199,
Yeh et al. 1995, Bom
1996, Lanner et al. 1'
Mudge et al. 1996,
inger et al. 1996). Wl
similarity among rel;
a companion paper (
RAPD technology t
and polyploidy witl
tulae of 1 of those g(
of RAPD data to coi
is, we believe, a nati
studies that have ma
comparisons.

Ma'ikrial^

We identified and
representing morphc
graphical spread of
Gollecting sites lor i
were determined lor
sia (Table 1), and r(|)

1998]

RAPD Con I Kiiu nox to Am iii;mii)i:ak Iaxonomy

Table 1. Location of sample collections and sample reference numbers.

Oolli'ttioii

Locafion and sample rcfcrciici' niiinhcr'

01. Spliainiiniria potcntilloidcs (.\. (S.\\\\)
\..\. Heller

02. Spluwroinchd iiolciitillokU's (.\. Cra>)
.\..\. 1 leller

03. Spluieroincria potciililloidcs i.\. Cray)
.\.A. Heller

04. Spluwroiiwria argentca NTitt.

05. Sphaeromerid urp,entea Niitt.

06. Sphaeronu'ria arg,entca Niitt.

07. Spliaeroiiwria capitata Nutt.

08. Sphaeromeha capitata Nutt.

09. Spluicniiiwria capitata Nutt.
10 Spliocnniicria capitata Nutt.

1 1. Si)luicn>incria dircrsifolia (D.C. Eat.)
H\(ll>.

12. SpliacrDiiuria divcrsifolia iD.C. Eat.)
Hxcll..

1.5. Si)lia(n>incria diicrsifolia (D.C. Eat.)
Rxdl).

14. Sphacnniu'ha nithiae Holnijiren.
Shultz, & Lo\vre\-

15. Splmeromeria nithiar Holmgren,
.Shultz, & Lo\\Te\

16. Sphaeroineria nidiiac llolnigren,
Shultz, & Lo\vTe\

17. Artemisia luduiiciunu Nutt.
1 S. Artemisia ludovicianu Nutt.

19. Artemisia ludoiiciana Nutt.

20. Artemisia spinescens D.C. Eaton

21. Artemisia spinescens D.C. Eaton

22. Artenmia spinescens D.C. Eaton
2.3. Artemisia spinescens D.C. Eaton
24. Artemisia tridentata Nutt. ssp.

vaseijaua (Kxclh.) Beetle
2.5. Artemisia tridentata .Nutt. s.sp.
vaseyana (R\cll>.) Beetle

26. Artemisia tridentata Nutt. .ssp.
vaseyana (R\dl).) Beetle

27. Artemisia tridentata Nutt. ssp.
wyaminfiensis Beetle & Young

28. Artemisia nova A. Nelson

29. Artemisia py^maea A. Gray

30. Artetnisia pypnaea A. Gray

•31. Artemisia cana Pursh. ssp. viscidula
(Qsterhout) Beetle

32. Artemisia cana Pursh. ssp. viscidula
(Osterhout) Beetle

33. Artemisia michaiixiana Besser

.34. Artemisia michaiixiana Besser

35. Artemisia michaiixiana Besser

36. Artemisia michaiixiana Besser

37. Artemisia binelovii A. Gray

38. Artemisia binelovii A. Gray

39. Artemisia hifielovii A. Gray

40. Tanacetiim vid<iare L.

41. Tanacctiun horeale Fisch. e.\. DC.

Hot Spriuiis I nil. Eureka Co., N\: M&S2428

4 km SolTlill City, Camas Co., ID. M&S 2425

1 km !•: ofHeese Ri\cr, U.S. High\va> 50, Lander Co., NV. M&S 2427

Point of Rocks, Sweetwater Co., \\T, M&S 2422

10 km SE of'Moimtain View, Uinta Co., \\% M&S 2424

Near Opal, Lincoln Co,, WT, H&Vs.n., 13 July 1995

E Sevier Road, Bnce Canxon, Se\ier Co., UT H&V .s.;i., 18 JuK 1995

N of Lookout Mountain, NlofVat Co., CO. M&S 2419

Mudd> Creek Bridge, Carbon Co,, WT, M&S 2420

1-80 e.xit 184, Sweetwater Co., WT, M&S 2421

Rockt;anyou, Utah Co., UT Il&\.v.;i.. 10 juK 1995

American Fork Canyon, Utah Co., UT H&\'.v.n., 10 July 1995

Santaciuin Canyon, Utah Co., UT H&V.v.ii., 10 July 1995 (also M&S 2041)
Refrigerator Cainon, Zion National Park, Washington Co., UT,

M.S,\",&Mu s.n.. 9 May 1995 (also M&S 1775)
"The Banacks, E Fork \ irgin Ri\er, Kane Co., UT. .M.S.&Mu .s.n.,

lONhiy 1995 (also M&S 1769)
Pine Creek, Zion National Park, Washington Co., UT, M,S,&Mu s.n.,

10 Mav 1995 (also .M&S 1774)

"The Barracks," E Fork \irgin Ri\ er Kane Co., UT, M,S,&Mu 2393

Salt Ca\e Hollow. Salt Creek Canyon, Juab Co., UT M&S 2437

Daniels Cau\on, Wasatch Co., UT, M&S 2431

Middlegate, Churchill Co., NV, M&S s.n., 6 June 1995

Desert E.xperimental Range, Millard Co., UT H&\' .s.n., S June 1995

5 Pony E.xpress trailhead, Faust, Tooele Co., UT, H&\' s.n., 5 June 1995
Secret Valley Mono Co., CA, M&S s.n., 10 June 1995

Hobble Creek Canyon, Utah Co., UT, G,W,M,&L 21492

Red Creek, Salina Canyon, Sevier Co., UT M&S 2149

Pine \alley. Washington Co., UT M&S 2177

5 km W of junction of Faust Road and Utah Highwa\' 73. Tooele Co., UT,

H&V s.»]., 16 August 1995
3 kmi E of Ruist. Tooele Co., UT, H&V .s.n., 16 .\ugust 1995
3 km E of Faust, Tooele Co., UT H&V s.n., 16 August 1995
E Sevier Road, Brvce Canyon, Sevier Co., UT, H&V s.n., 18 July 1995

Daniels Sunnnit, Wasatch Co., Utah, M&S 2430

Warner Pass, Lake Co., OR, M&S 2436

Snowbird, Little Cottonwood Canyon. Salt l>ake C^o., UT, H&V .s.n.,

11 .\ugust 1995

Above Kingston. Lander Co., N\; M&S 2429

Lamoille Cianxon. Ruby Range. Elko Co., N\". M&S 2426

Snowbird, Little Cottonwood Canyon, Salt Lake Co., UT. H&V. s.n.,

1 1 August 1995 (1.5 km from .33)
Utah Highwax- 12, Milepost 36, Garfield Co., UT H&V s.n., 18 July 1995
Utah Highwav 12, Milepost 51, Garfield Co., UT H&V s.n., 18 July 1995
North Creek Road, Garfield Co., UT H&V.s.n., 18 July 1995
Greenhouse grown from Bonn Botanical Garden, nati\e population from

.Nordrhein-Westfalcn, Eifel, Blanki-nheimerdorf, Germany 0613
Greenhouse grown from Brunn, Czech Republic, Hortus Centralis Cultura

Herbarum Mediicanun Facultas, Medica, Uni\'ersitas, Masankiana 770

(native population site unknown)

■'Initi.ds lor the collectors are G = Sherel Goodrich, L = Mont E. I,<\
C. Sanderson, \' = Renee \an Buren. and W = .\lnia II W'iiiward

11 = Kinil)all T llari^er. M = E. Durant Mc.Wuir. Mm = Joanne Mudge, S= Stewart

Great Basin Natur.\list

[\'()lume 58

all reagents except DNA to identif> ambigu-
ous markers. Amplified products were sepa-
rated and \isualized using metaphore/ agarose
gel electrophoresis. DXA was stained with
ethidium liromide and bands were pho-
tographed under UV light. Amplified bands
were scored from photographs and recorded
as presence or absence of bands of the same
molecular weight (Fig. 1). The DNA size marker
pUC-19 207 (Biosynthesis, Inc., Lewisville,
TX) was added every 7th lane for reference
and ease in scoring gels. A control lane
(included all reagents but DNA) was also
included (Fig. 1).

Analysis of Amplified
DNA Products

We used the NTSYS-pc (version 1.80) sta-
tistical software package to analyze amplified
DNA products (Rohlf 1993). Presence or ab-
sence of specific DNA bands (markers) was
analyzed for percent similarit>'. To produce a
similarity' coefficient matrix for all samples in
the analysis, we used Jaccard's coefficient of
similarity (Jaccard 1912). UPGMA clustering
analysis (NTSYS-pc, SAHN) was used to gra-
phically show similarity among samples. A
phenetic tree (NTSYS-pc, TREE) was gener-
ated to display percent similarity relationships
among samples. Mean similarity \alues (with
the standard deviations for each) were calcu-
lated for populations of each species, each
genus, and among the .3 genera. For making
comparisons of means within and between
genera, species (and subspecies) population
means were used. Many of these means were
compared using / tests (Woolf 1968). Percent-
age values were arcsin translonncd lor statisti-
cal analyses but were converted I)ack to pci-
cent \ahu's foi' I'cporting.

Kk.sults

Twenty primers (Table 2) produced 238
infonnative, scorable markers that were used
to determine similarity among the selected
Sphaeromeriu. Artetni.sia, and Tanaccliim ta\a.
Presence and absence data were used to com-
pute percent similarity and to gemiatc a
phenogram (Fig. 2). The phenogram clearK
distinguishes among the 3 genera of interest
with the exception of a group at the to\) ol the
lig\n-e in which Spluwroineria potcntiU()i(Us
and Artemisia spiiicsccns are grouped. The

m 1
.i li
mi

mi ■
in:
1 1 :
t II

1 4*.".i:

1 . S. potentilloides

2. S. potentilloides

3. S. potentilloides

4. S. orgenteo

5. S. orgenteo

6. S. orgenteo

—pUC- 19 marker

7. S. copitoto

8. S. copitoto

9. S. copitoto

10. S. copitoto

11. S. diversifolio

12. S. diversifolio

— pUC-19 marker

13. S. diversifolio

14. S. ruthioe

15. S. ruthioe

16. S. ruthioe

1 7. A. ludoviciono

18. A. ludoviciono

— pUC-19 marker

19. A. ludoviciono

20. A. spinescens

21 . A. spinescens

1 22. A. spinescens

1 23. A. spinescens

1 24. A. tridentoto ssp. voseyono

125. A. tridentoto ssp. voseyono

126. A. tndentato ssp. voseyono

127. A. tridentoto ssp. wyomingensis
I — pLIC-19 morker

128. A. novo

129. A. pygmoeo

30. A. pygmoeo

31. A. cono spp. viscidulo

32. A. cono spp. viscidulo
1 33. A. michouxiono

pL)C-19 marker

|34. A. michouxiono

1 35. A. michouxiono

|36. A. michouxiono

37. A. bigelovii

1 38. A. bigelovii

1 39. A. bigelovii
40. T. vulgore

|4l . T. boreole
-pUC-19 morker
Control

hiH. 1. Hiotoiiiiipli ol'iii-l ()P.\\\'-19. Populations and htxa
Mc icIcntilU'cl to tlu' riijlit oli-atli laiu' (tlic miinluTS ivior
lo populations ol'i'al)lc 1). Moliviilar markiT lanrs (pl'CN
19 207) and a blank fOMtrol lam- arc also lahfk'd lo the
riiiht.

plu-nogram (Fig. 2) also strongly groups the
populations of each ta.xon. Percent similarity
among populations of a single taxou, among
species within a genus, and among the 3 gen-
era of interest is repoited in Tables 3 and 4.

1998]

KAPD COMKIBL IICJN TO AM llLIMlDliAli T.LXONOMY

Taui.K 2. Primer name, scciiieiice, and iiiimhtT of marki'is
iieiu-ratfcl from catli primer used for amplification of sam-
ple f:)NA.

Number

Primer name'

Primer secjnenee (5'— >3')

of markers

()P.VP-().5

(;actc,cx;agg

13

()l^.Vf"-()f

ITCCXnCGCC

11

()P.V1"-()(S

cc:(;tcc;ctga

13

()P.VI-()S

rCK.rGGTGGG

10

()I^Vi■-ll

c:cac;atctcc

11

()i^\T-12

CTGGGTAGCC

15

()i^Af"-1.3

GTGGTCGA.AG

10

()PAT-14

c;tgccgcact

13

()PAT-15

tgac:gcacgg

11

OlHT-fT

AGCGACTGCT

10

OPAT-fS

(;c:agctgtga

13

Of^AT-fy

AC:C:.\.\GGCAC

9

OPAL-03

ACC;.A.\.\CGGG

10

()PAL-()4

c;c;gttctgtc

9

()PAL-()7

AGACCCTIGG

9

()PAU-()9

ACGGCC.Jl\TG

15

OPAL- 11

CTTCTCGGTC

12

()PAL-15

TGCTGACGAC

16

O PAW- 19

ggacacagag

14

OPA\-()9

GGA.\GTCCTG

11

Total mmber of markers

23S

"OptTon Tcclinolocifs. Inc.. .\lameda. C.\

Tables 5 and 6, lespcctix c^K; report siniilaritie.s
am()n<4 the .species of S))Juii'r())ncii(i and Aiie-
inisia. \alues in Tables 3 and 4 are the percent
similaiit\ to be expected for groups of plants
at \ arious le\ els of classification in the tribe
Antheniideae. A full data matri.x is axailable
upon recjuest from the senior author.

The chromosome number for S. diversijuUa
from Santaquin Canyon, Utah (McArthur &
Sanderson 2041), is 2n = 18, the same number
(as n = 9 or 2n = 18) for all other reported
Sphacroiiwha species [S. cana as Tanacetiim
canum, S. nuttallii as T. niittallii, S. potentil-
loides as T. potentilloides, and S. argentea as T.
argentea (Powell et al. 1974), and S. argentca
(Sanderson et id. 1984) and S. nithiae (\\cAi-\\\uv
et al. 1989)].

Discussion

Inferences from Fli\PD Data

INTKHPOPI TATION SIMILARI'IT. — Within the
genera Sphaeromerki and Artenmia, interpop-
ulation similarit) is 72.4 ± 2.3% (.s) (Table 3).
This is a reasonable value for populations of
the same species using our s\ stem ot anal\ sis.
\'an Buren et al. (1994) reported about 80%
similarity among populations of buttercups
{Ranunculus spp.). Gang and Weber (1995)
reported appro.\imately 70% similarit>- among

populations of white-stenuued rubber rabbit-
brush (Chn/.sotlunniui.s nauscusus ssp. hololeu-
cu.s), and we found about 55% similarity in
sagebrush (Artcinisia subgenus Tridcntatae)
populations in a companion stucK (McArthur
et al. 1998) using similar analytical technicjues
to those employed in this stud)'. The patterns
were similar for both genera: S))haeromeria
populations ranged from 53% to 85% similar-
it); Arteinisia populations from 58% to 87%
similarity.

SlMlL.\RlTY WITHIN CENERyV. — Siuiilarit) of
species within genera provided some instruc-
tive and interesting information (Table 4). The
5 species of SpJiaerouieria were 20.7% similar
and except for S. potentilloides clustered on the
same stem of the phenogram (Fig. 2). W'hen S.
potentilloides is removed from the analysis,
the mean congeneric percent similarity for
Spluieromeria is 24.7 (n = 6, s = 6.5). Sphaero-
meria potentilloides has been recognized as
somewhat distinct from other Sphaeromeria
species bv earlier workers (Holmgren et al.
1976, Cronquist 1994). Rydberg (1916) included
S. potentilloides in the genus Vesicarpa, and
Asa Gia\ included it in Artemisia but placed
other currently recognized species of Sphaero-
nieria in Tanacetum (Torrey and Gra\' 1843,
Holmgren et al. 1976). We compared the RAPD
markers of the sampled S. potentilloides popu-
lations with all other Sphaeroineria populations
by subjecting those values to a t test. Results
indicate that S. potentilloides is no more simi-
lar to its congeners (.y = 14.9% similarit\ j than
it is to the other populations (.v = 15.4% simi-
larity) included in our study, t = 0.27, p >
0.80 (data not shown, Init see Table 5 for com-
parison of means). It might be well to resur-
rect R\dbcrg's Vesicarpa for S. potentilloides.
The relatively high RAPD marker similarity
between S. diversifolia and S. ruthiae (Table 5)
is consistent with their morphological and
habitat preference similarities and with appar-
ent volatile oil content (Holmgren et al. 1976,
McArthur et al. 1989, unpublished).

The subgeneric ta.\onom\ oi Aiieniisia fol-
lows a tradition begun b\ Besser (1829) where-
in he separated sections based on various com-
binations of disc and ray flower occurrences
and fertilit); Besser's 4 sections {Ahrotanum,
Al}sinthiunh Drancunculus, Seriphidium) have,
in the main, been retained. How e\ er, R\ dberg
(1916) elevated them to subgenera and created
subordinate sections, and Poljakov (1961)

Grkat Basin Natl halist

[Volume 58

0.00

I

0.25
I

0.50
\

0.75

I

1.00

I

L

01 S. potentilloides

03 S. potentilloides

02 S. potentilloides

20 A. spinescens

21 A. spinescens

22 A. spinescens

23 A. spinescens

04 Sphaeromeria argentea

05 Sphaeromeria argentea

06 Sphaeromeria argentea

07 S. capitata

1 1 S. diversifolia

12 S. diversifolia

13 S. diversifolia

14 S. ruthiae

15 S. ruthiae

16 S. ruthiae

08 S. capitata

09 S. capitata

10 S. capitata

24 A. iridentata ssp. vaseyana

25 A. tridentata ssp. vaseyana

26 A. tridentata ssp. vaseyana

27 A. tridentata ssp. wyomingensis

28 A. nova

31 A. cana ssp. viscidula

32 A. cana ssp. viscidula

29 A. pygmaea

30 A. pygmaea

37 Artemisia bigelovii

38 Artemisia bigelovii

39 Artemisia bigelovii

17 A. ludoviciana

18 A. ludoviciana

19 A. ludoviciana

33 A. michauxiana

34 A. michauxiana

35 A. michauxiana
i6 A. michauxiana

40 T. vulgare
4 1 T. horeale

Fig. 2. PhcnoKrain produced iisiiin Jaccard s coi'flicicMit of'similarit) and lU'CMA tliistcrin^ aiuiKsi.s (\T.SVS-iu) li
all 41 samples included in this study. Nuniliers preceding tlie species identify indi\ idual populations listed in iahle 1.

united Ahrotanum and Ahsintliiuiii into the and Plnnnner 197S, and Me.Vrtlnn- 1979 for a

.sub^enu.s Artemisia. MeArlhur et al. (1981) more- tlioiongli ri'\ie\\ and relerenee.s). WchiT

.separated Hydberj^'s .seetion Tridcntatae from (1984) and Ling (1995!)) eonsider 7hr/r;i/a/m' a

the Eura.sian .suhj^enu.s Sehi)hi(liiim ha.sed on portion of Scni)hi(liiiin. Seaman (1982) and

karyotypie, ehemota.\onomie, and di.strihiitional jefrreN ( 1995) snpport, as we do, tlie indepen-

differenee.s and reeoKni/.ed the .seetion al the di-nee lAThdcnldtdc from Scripliidiinn. We ree-

suhgenerie level (.see Fersson 1974, MeArthur ognize 4 subgenera {Artemisia, Draticunculus,

1998]

liVPD COMHIBITION TO AM IIKMIDKAK TAXONOMY

T\Bl.l 3. Mean percent similarih' among populations.-'

InUTpopul.ilion

siiiiil.irit)

.v-

Mean

s

S))luiert)mch<i }H)tcntiUoklcs

3

76.7

11.6

Sphacroiiwria ar^cnteu

3

84.8

7.6

Splwcroiiwria capitata

6

52.8

2.1

SphacrDiiuria diversifoUii

3

76.0

5.4

Spluwroiiurhi nithiac

3

82.3

4.8

Arti'tni-sia hidoiiciana

3

80.3

8.8

Artemisia inicliaiixiaiw

6

73.1

3.9

Artcinisid spiiicsicits

6

63.5

12.8

Arti'ini.sid tridcntata ssp.

lasctjaiKi

3

80.8

1.6

Artciuisid cana ssp.

vificidula

1

58.0

—

Artemisia pij^maea

1

87.0

—

\rtemisia hi^elovii

3

83.5

3.4

Mt'an inteqioiiulational

sin>ilant\

41

72,4

2.3

Mean w itliin species

12

74.9

11.1

^Includes all spt'cics with more than 1 ixjpiilation sampltd. .Sec Table 1.
''JV for each sijecies is that of all comparisons, e.g., immber ol populations per
species x number of populations per species minus 1 divided by 2. .V for
mean interpopulational similarit)- is the sum of species populations. .V for
mean widiin species is number of species.

Scnj)hi(limii. Triilvntatae). Greger (1978) held
a .similar, if le.s.s formal, view. Repre,sentati\'e
.speci(.>s from the 3 subgenera that occur in
\orth .\merica iAtiemisia, Drancunculns. Tri-
(Iciitafae) were included in this stud\\

The 8 species (9 taxa including 1 subspecies)
o^ Artemisia included in this study are 26.7%
similar (Table 3). Artemisia species cluster in 3
main stems in the phenogram (Fig. 2). Those
stems correspond to the 3 subgenera to which
the species belong. The only representative of
subgenus Drancunculus included is A. spiue-
sceiis. In our phenogram (Fig. 2) it clusters
with S'. potciitilloidcs but at a relatively low
coefficient of similarity. Nuttall (1841) origi-
nalK placed A. spinescens in the monotypic
genus Picrothammis. The distant placement of
A. spinescens from other Aiietnisia in the phen-
ogram (Fig. 2) is in line with Bremer s (1994)
statement that Artemisia is "known" to be a
polyphyletic genus. Two subgenus Artemisia
species were included, A. hidoviciana and A.
michauxiaiia. and the\' form a rather tight
group (Fig. 2, Table 6).

Si.x taxa (5 species) of the subgenus Trideti-
tatae were included in this stud\ : A. tridentata
ssp. vaseijana. A. t. ssp. icyomin<!,ensis, A. nova,
A. cana ssp. viscidida, A. pij^^maea, and A.
bigelocii. The latter 2 species have been con-
sidered questionable members of Tridentatae.
Using various morphological, anatomical,

T.\BLI£ 4. Mean pefcent siniilarit\ williin and between
genera.

.V' Mean v

Siniilarit> w ithin a single genus

Splweromeria 10 20.7 7.1

Artemisia 36 26.7 16.3

Tamicetum 1 88.9 —

Mean'- 2 24.0 4.2

Siniilarit\ between genera

Sphaeromeria/Artemisia 45 18.0 3.5

Sphaeromeria/Tanacetiim 10 7.0 2.2

Artemisia/Tanacetum 18 7.0 2.5

•'.Y for similarit\ witliin a single genus is the number of species (and subspecies)
X number of species (and subspecies) minus 1 divided by 2. A' for similarit\'
between genera is the product of the luuiiber of species (and subspecies) in
each genus.

''This mean includes only Spfuwromirid and Arletnisia because Tanacetum
species behaved as if they were pupuiatiims of a single species and their sam-
ple number (2) was low.

chromosomal, and chemical criteria, Hall and
Clements (1923), Moss (1940), \\\u-d (1953),
Beede (1960), Hanks et al. (1973), McArthur
et al. (1981), Shultz (1986), and Cronquist
(1994) included A. pygmaea in Tridentatae ( =
North American Seriphidiinn of some treat-
ments); whereas Holbo and Mozingo (1965)
and Geissman and Invin (1974) excluded it.
Likewise, Moss (1940), Beetle (1960), Hanks
et al. (1973), Geissman and Invin (1974), and
McArthur et al. (1981) included A. bigelovii in
Tridentatae: Hall and Clements (1923), Ward
(1953), Holbo and Mozingo (1965), Shultz
(1986), and Cronquist (1994) excluded it. Both
A. pijgmaea and A. bigelovii can be included
within Tridentatae based on FL\PD data (Fig.
2, Table 6). Each taxon has more DNA marker
similarity to some sister Tridentatae species
than others, e.g., A. bigelovii with A. pygmaea
and A. cana ssp. viscidida; A. pygmaea with A.
cana ssp. viscidida and A. tridentata ssp. vaseij-
ana. Our data do not support Beetle's (1960)
suggestion that A. nova is most closeK allied
to A. pygmaea.

We subjected all Tridentatae taxa to t tests
in which each was compared with other mem-
bers of the group and with all non-Tridentatae
Artemisia taxa in this stud\ with respect to
percentage similarit>" based on DNA markers.
Results (data not shown) gave a mean percent-
age similaritx of 40.5 ± 16.0 among species of
Tridentatae. In contrast, species of the Triden-
tatae were only 16.1 ± 1.7% similar to non-TH-
dentatae taxa {t = 6.7, /; < 0.01). A comparison
of A. spinescens with other Artemisia species
gave an average percent similarit}' of 15.6 ± 3.0.

8

Great Basin Naturalist

[Volume 58

Table 5. Interspecific similarity in the genus Sphaeromeria. Each xahu- in the table is an axcraKc based on 9-12 inde-
pendent comparisons. Similarity is based on HAFD markers.

Species'*

SPPO

.3

SPAR

3

SPCA
4

SPDI

3

SPRU

3

S. potentilloides
S. argciitea
S. capitatd
S. (liiersifolia
S. ruthiae

15.8
16.4
13.7
13.3

24.5
22.1
22.3

27.9
15.9

35.3

"Species designations: SHPO = Splwcroiiwriii i)i)tcntilloi<lc.s. SI'AR = S. arnfutcd. SPCA ■
^N — number of populations.

S, cupiUilii. SPDI = S, iliirrsijoliti. SPRl' = S. ra//ii

A similar comparison between the 2 su])genus
Artemisia species (A. ludoviciana and A.
luicluiuxi(nui) and other Aiiemisia species gave
a mean percent similarit\- of" 15.0 ± 2.3. The 2
subgenus Artemisia species were 44.3% simi-
lar to each other (Table 6). These results and
inspection of the values presented in Table 6
support the integrity of the subgenera as rec-
ognized herein, especial!) for subgenus Tri-
dentatae, which was more thorougliK' repre-
sented in the stud\ than were the other sub-
genera.

Two Tanacetum species were sampled, T.
vulgare and T. horeale (Table 1). By DNA
marker analysis they were 88.9% similar (Fig.
2, Table 4), which is as similar as populations
of the same species for the other ta.\a sampled
in this study (Fig 2, Table 3) and as similar as
conspecific populations in a similar study of
portions of the genus Ramnwidus (Van Buren
et al. 1994). Both Tanacetum species are wideK
distributed in Eurasia, and T. vulgare is natu-
ralized in temperate North America (llnlteii
and Fries 1986). Some, but not all, authors con-
sider T. horeale mainly an Asian geographical
variety of T. vulgare (Hulten and Fries 1986
and references in Coldblatt 1981, 1984, 1985,
1988 and Coldblatt and Johnson 1990, 1994).
Our 2 study popuhitions contrasted (hamati-
cally in leaf niori)hoh)gy {T. vulgare had much
finer, pinnately dissected leaves). UnlortnnateK,
we were unable to sample native North Amer-
ican Tanacetum material. However, all natixc
North American species o{ Tanacetum arc mciii-
bers of the he.xaploid (n = 27) T. hipiiinalum
complex (Powell ct al. 1974, K\'hos and Kaxcii
1982), whereas nmncious cliroiiiosoinc counts
for T. vulgare and T. horeale haxc show ii these
taxa to be exclusively n = 9 diploids (l'ed( ro\
1969, Goldblatt 1981, 1984, 1985, 1988, Cold-
blatt and Johnson 1990, 1994). As one goal ol

oin- research was to compare Sphaeromeria
with Tanacetum and all known Sphaeromeria
chromosome counts are diploid, n = 9 (Powell
et al. 1974, McArthur et al. 1989), we think that
comparisons made here among the Spluiero-
meria and Tanacetum populations are appro-
priate and that lack of a comparison of the T
hipinnatum complex with Sphaeromeria is not
a critical omission.

Similarity between genera. — The per-
cent similarit\ of DNA markers between the
genera of interest is given in Table 4 and Fig-
ure 2. These data support the established sep-
aration of the 3 genera. When the genera are
compared (Table 4), the percent similarit)
between Sphaeromeria and Artemisia (18.0%)
is greater than for other comparisons among
these genera (7.0% similarity for both the Spluie-
romeria-Tanacetui)} and Hie Artemisia-Tanace-
tum comparisons). These data are in full sup-
port of the Holmgren et al. (1976) conclusion
that Spluwromeria is more closcK alliliatcd
with Artemisia than with Tatuieetwn.

In the phenogram (Fig. 2), the top group
consists of both Sphaeromeria and Artemisia
samples; howe\'er, tlie\ share relatixcK little
similarity with each othei- (<2(F()- lu contrast,
the major group of Sphaeromeria, the 2nd
major stem ol Figure 2. and the balance ol the
Artemisia samples, the ord and 4th major
stems of iMgure 2, cluster wx-ll abo\ t- the 20'"^
similarit) lexcl. Ihat S. potentilloides and A.
spinesceus are on the sanu- stem (lug. 2) ma\'
relleet their iiiii(|neiiess in regard to species
within their own genera, as we ha\e discussi'd
in the |)re\i()us section, rather than common
pli\ logeiix lor those 2 taxa. The 3rd major stem
of I'igine 2 consists ol samples of subgenus
Tridcnidlac. This group is sliglitK more similar
to the main Sph(U'romeria stem than to other
Aiiemisia and ma\ therefore be an appropriate

1998]

1-LVPD COMKIliLTlON lU AMII1;MI1)1; AK T.VXONOMV

Tabli-; 6. IntcTspecifk' similarih.- in the genus Artetnisia. Each value
ik'ut comparisons. Similarih' is based on RAPD markers.

the tabic is an average based on 9-16 indepen-

.Sjiecies'

ARSP

ARIl

AR\II

AinR^

ARTR\\

ARCA^

AR.NO

ARPY

ARBI

'.Vh

4

■3

4

.5

1

2

1

2

3

\HSP

—

AKIA

119

—

.MiNll

10.4

44.3

—

ARTH^

18.0

17.4

18.3

—

AiriH"

15.4

1.5.6

14.4

70.7

—

ARCA\

18.2

15.7

17,7

.50.9

40.0

—

ARXO

16.4

16.5

17,1

60.4

68.4

48.9

—

ARPY

16.1

12.5

14 1

35.4

34.1

37.3

33.9

—

ARBI

18.4

14.5

14.1

23.6

22.1

27.6

23.6

30.3

—

■'Spt'cies designations: .\RSP = Artetuviia xpiiiescens, .\RLL' = A. huloiicianti. .\RMI = A. mich
wijomingensLi. ARC.\^ = A. cana ssp. viscidula. .\RNO = .A. noia. .\RPY = A pyemia. ARBI
''.V = number of populations.

ARTR^ = A. IrulenUita ssp. vaseyana, ARTR^^ = A. I.
A. bi"lovii.

place to look lor the closest relatix es ol Sphae-
romeria, although our expectatiou was that
Sphacroiiicria should be closer to the less
wood) A. hidoviciana complex.

Anthemideae Distributiox

AND PHYEOGENV

Anthemideae is one ol the more morpho-
logically and chemically specialized and ph\ lo-
geneticalK adxanced Compositae tribes (Cron-
quist 1955, Greger 1978, Mc.Aiihur 1979, Zdero
and Bohlmann 1990). ,Although die Compositae
is one of die largest families of flowering plants,
it became an important part of the earth's flora
relati\('l\ late — in the mid-Tertian (Ra\ en and
.Axelrod 1974, Wagenitz 1976). Ra\en and Axel-
rod (1974) postulate an origin for the family in
northern South America because the primitixe
generalized tribes Heliantheae and Mutisieae
are concentrated there. De\ore and Stuess\
(1995) recentl\- re\iewed macromolecular data
(cpDNA restriction site analysis, rbcL sequence
data) that support a South American and south-
ern hemisphere ancestn lor the lamily. Regard-
less of its place of origin, however, the family
rapidK. in geological terms, became estab-
lished worldwide. Wagenitz (1976) suggested
that the principal exolution and di\ersification
in the family took place in .\eric enxironments
and in tropical mountains. In general, the fam-
il\'s migrations were achieved when the conti-
nents were close to their present positions
(Ra\"en and .Axelrod 1974). The great Eurasian
and North .African landmass is the center of
di\ersit>' for several tribes including Anthemi-
deae (Bailev Hortorium Staff 1976, McArthur

1979). Of the principal Anthemideae genera,
only Artemisia, Achillea, Matricaria, and Tana-
cetinn ha\e a natural North American distribu-
tion (Willis 1973, Baile\ Horiorium Staff 1976,
McArthur 1979). Of these 4 genera, Artemisia
is b\' far the most common and diversified in
North America. Each of these genera, includ-
ing Artemisia, has circumpolar distributions
with much stronger di\ersification in Eurasia
than in North America. This information is
consistent with our DNA marker data in sug-
gesting that Sphaeromeria is a distinct genus
aligned more closely with Artetnisia than with
other taxa.

Acknowledgments

We thank Ralph Andersen, Paul Evans,
Harald Greger, Ralph Moore, Joann Mudge,
Jeff Ott, Ken Redshaw, Daria Sidles, and John
Tw ibell for assistance with \arious parts of this
work. Zion National Park personnel kindly
peniiitted and assisted our collection of plant
materiiils. GKxle Blauer, G.K. Brown, Carl Free-
man, Joann Mudge, Leila Shultz, and an anon-
ymous reviewer pro\'ided helpful rexiews of
an earlier draft of the manuscript. The work
was partially funded by U.S. Department of
Agriculture CSREES competiti\e grant 91-
98300-6157 and b\ cooperatixe agreement
INT-95013 RJVA between the Intermountain
Research Station (now Rocky Mountain Re-
search Station) and Brigham \bung Universit\'.
The use of trade or finii names in this paper is
for reader information and does not imply
endorsement by the U.S. Department of Agri-
culture of an\ product or sen-ice.

10

Great Basin Naturalist

[Volume 58

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Received 19 March 1997
Accepted 28 August 1997

Great Basin Naturalist 58(1), © 1998, pp. 12-27

RWDOMLY AMPLIFIED POLYMORPHIC D\A ANALYSIS (R\PD) OF
ARTEMISIA SUBGENUS TRIDEXTArAE SPECIES AND HYBRIDS

E. Duraiit McArthurl, Joann Mudge^ - ^ Renee \'an Buren^-*,
W. Ralph AiulcTsen-, Stewart C. Sanderson^ and Da\ id C. Babhel^-^'^

Abstract. — Species oiArteinLski (subgenus Tridcutatdc) dominate inucli of western Xortli America. The genetic varia-
tion tliat allows this broad ecological adaptation is facilitated by h\ bridization and poh i)loidization. Three separate studies
were performed in this group using randomly amplified poKinorphic DNA (RAPD). Fifty-se\en 10-mer primers generated
nciirly 400 markers from genomic DNA obtained from leaf tissue. These studies were (1) a measure of the varialiilit>- of
plants within and between populations and between subspecies using 5 A. trklentata ssp. ivyomingensis populations, 2 A.
cana ssp. cana populations, and 1 A. cana ssp. viacklula population; (2) an examination of the hypothesis that tetraploid (4x)
Artemisia tridentata ssp. vaseijana derives de novo from diploid (2.x) populations via autopol\ploid\-; and (3) an examination
of the validitx of the status of putative hybrids diat have been produced by controlled pollination. These latter hybrid com-
binations— A. tridentata ssp. tridentata x A. t. ssp. vaseijana, A. t. ssp. wtjoniingensi^ x A. tripariita, and A. cana ssp. cana x
A. tridentata ssp. ivyomingensis — were made to combine traits of parental taxa in unique combinations with possible man-
agement application. R/VPD marker data were subjected to similarity' and UPGMA clustering analyses. rL\PD markers
were effective in measuring genetic diversity at different systematic levels. Individual plants within a poi)ulation were
approximately 55% to >809f similar to one another; populations within subspecies ga\e corresponding \alues of similarity,
probably a result of the combined effects of large population sizes and wind pollination. The 2 subspecies of A. cana were
approximately 45% similar At least some 4v populations of A. tridentata ssp. vaseijana apparently deri\e de novo from 2.v
plaTits based on their being embedded in 2v phenogram groups, thus reinforcing e\idence that autopoly ploidy plays an
important role in Tridentatae population biology. Two (A. tridentata ssp. tridentata x A. t. ssp. vaseijana and A. cana ssp.
cana x A. tridentata ssp ivijomingensis) of the 3 piitati\ e hy brid combinations were confiiTUed to include hy brids. These
hybrids may have potential in management applications, .additional use of FL\PD technology combined with other tech-
niques may be useful in delimiting genetic characteristics and in guiding artificiiil selection in die Tridentatae.

Key words: Artemisia, Tridentatae, fL\PD. hybridization, diploid, tetraploid. polyploid, autopolyploidy.

Subgenus Tridentatae oL\rteinisia is a ajroup
of phmts centered on the landscape-dominant
A. tridentata complex. There have been several
treatments of this group, e.g., Rydberg 1916,
Hall and Clements 1923, Ward 1953, Beetle
1960, Shiiltz 1986, Cron(iuist 1994; we recog-
nize 11 species and 13 subspecies (McArthm-
and Plummer 1978, McArthur 1979, 1983, 1994.
(Goodrich et al. 1985, Rosentretcr and Kelse\
1991, Winward and McArthur 1995). Lhe Tri-
denlatae are built upon pol\ ploidization and
hybridization (Ward 1953, Beetle 1960, Hanks
et al. 1973, McArthur et al. 1979, 1981, 1988,
Winward and McArthur 1995). ILRrid zones
(see Harrison 1993 for sununar\ and rt4er-
ences) l)etween subspecies of A. fridcntala air
yielding information about the nature, stabilily,
and (Knamics of these zones (McArthur el al.

1988, Freeman et al. 1991, 1995, Craham et al.
1995, Messina et al. 1996, \\'ang et al. 1997),
an area of ciureut interest among e\ olutionar)
biologists.

Randomh' amplified i:)ol\ niorphic DXA anal-
ysis (RAPD) is \ielding useful information
about the population biolog), classification,
and genetic structure of plants (Williams et al.
1990, 1993, Fritsch et al. 1993. Le\ i et al. 1993.
Santos et al. 1994, \im Bmen et al. 1994, Brad-
shaw et al. 1995, Gang and Weber 1995. Yeh
et al. 1995, karp et al. 1996), including the
natuic and extent ol natural and controlled
hybridization (linen and llelentjaris 1993,
Hiadshaw et al. 1994. Kennard et al. 1994,
Dean and .\niold 1996, Lin and Hitland 1996,
\lndge el al. 1996, Smith et al. 199(i. Daehler
.nid Strong 1997). This papei" reports the usi-

ISlirul) Scic-iiccs Lilioralon, Kockv VIdiiiitaiii Ucscin li Slalioii, I'linsI Sciauc, I iiitcil Stales Drpaitiiiciit i)l AKrinilHiic. T;1.5 N. .'jlX) Iv, PiDVii. IT H KilMi

^ncparliiiciil of boluiiv ami RaiiKc SciciHc. Hri«liain Vduiiu University, Provo, UT H-l(i<l2.

■'Prc'Sfiit address; Uepurtineiil ol AKroiiomv and Plant (ieiietics. University ol Minnesota, St. Paul, MN .5.5108.

••Present address: Department of Life Scienee, Utali Valley Stale College, Oreni, L'l" H1I)5K.

•^Present address: ColleKeof Osteopatliie Medicine, Western University of llealtli Seienees, h na, C.V 9l7(i().

12

1998]

RAPD Anaiasis oi' Artemisia Spec;ii:s and Umikids

13

of uciioiiiic RAPD niarkrrs in bt'ttcr undcr-
staiuliiiu the iiaturi- of populafion variation.
poK ploi(K. and li\ hridi/.ation in tlu- Iridcn-
tatac 1)\ reporting; on the resnlts ol 3 stuchcs;
(1) DN'A marker \ariation anions populations
olA. tridcntata ssp. wyoiniii<ii'ii.si,s and hetsveen
subspecies of A. cami; (2) DNA marker \aria-
tion among diploid (2a:) and tetraploid (4.v)
populations of A. tridentata ssp. vascydna in
addressing the possible dc novo origin ol 4.v
i:)()pulations; and (3) DNA marker determina-
tion of the status of putati\e artificial hybrids,
.A. tridentata ssp. tridentata x A. /. ssp. vasey-
(intt. A. tridentata ssp. wyoiningensis x A. tri-
])artHa. and A. cana ssp. cana x A. tridentata
ssp. wyomingensis. We have previously exam-
ined these problems using morphological char-
acteristics (McArthur and Welch 19cS2, Free-
man et al. 1991, 1995), chemistn (Hanks et al.
1973, Welch and McArthur 1981, Weber et al.
1994), and anaKses integrating chemical and
morphological approaches (McArthur et al.
1988, 1992, Graham et al. 1995, Messina et al.
1996, Wang et al. 1997). A companion paper
addresses the use of RAPD anaKsis in the sys-
tematics of Artemisia and 2 sister genera,
Sphaeroineria and Tanacetuin (McArthui- et al.
1998).

M.\TERIALS AND METHODS

Plant Materials

Plant populations sampled and used in the
3 studies together with their taxonomic affilia-
tion are listed in Table 1. We obtained these
plant materials from the following: natural
populations, samples of natural populations
that had been propagated from seed in our
greenhouse, outplantings of progenx- from nat-
ural populations in experimental plots and
common gardens, and putative artificial hvbrids
grown in the greenhouse and at outplanting
sites. The putatix e hxbrid seed was obtained us-
ing methods described prc\iousl\' (McArtliur et
al. 1979, 1988, NoUer and McArthur 1986), i.e.,
placing inflorescences with dehiscing anthers
in doubled pollination (white baken) bags just
before anthesis of the maternal parent. We re-
mo\ ed pollination bags 3 wk later and collected
seed before the heads shattered. Representative
\ oucher samples for all 3 studies are deposited
in the Shiaib Sciences Laboratory Herbarium
(SSLP). Leaves for DNA extraction and analysis
were collected from indi\idual plants during

the 1991-92 growing season. We extracted
DNA either from fresh material immediately
after collection (<3 h) or from material that
had been immediateK' frozen in li(juid nitro-
gen and stored at ultra-cold temperatures
(-80°C) until the tissue was extracted. DNA
anahsis was performed on indi\ idual plants
and on bulked population samples (5-8 plants).
Chromosome counts were made to assist in
hxbrid confirmation using the techniques de-
scribed b\' McAi'thur and Sanderson (in review).

Study 1. — We examined DNA marker vari-
ability in populations at 2 different taxonomic
levels (Table 1). First was the population le\el
wherein we examined 5 different populations
of A. tridentata ssp. wyomingensis. The 2nd
level was between 2 subspecies of A. cana (2
populations of A. cana ssp. cana and 1 popula-
tion of A. c. ssp. viscidula). We used both indi-
vidual plants and bulked samples for DNA
marker analysis.

Study 2. — We examined DNA markers from
7 A. tridentata ssp. vaseyana populations (Table
1, Fig. 1). Several locations where diploid (2.y)
and tetraploid (4.y) populations of this taxon
grow parapatricalK' or sympatricalK' have been
discovered (MciAi-thur and Sanderson in rexiewj.
Some of those populations are included in this
study (Table 1, Fig. 1). Initially, we thought the
Hobble Creek location, which includes plants
from both the mesic can>()n bottom habitat
and the more xeric south-facing slope habitat,
included 2.r and 4x populations. However,
additional cytological study (McArthur and
Sanderson in re\'iew, unpublished) has shown
that the Hobble Creek location is essentialK
2.r with only an occasional 4x plant present.
We kept the Hobble Creek population in the
stud\- for additional comparison of A. triden-
tata ssp. vaseyana DNA markers.

Study 3. — We examined DNA markers from
3 artificial hxhridization experiments (Table 1).
The 1st h\brid is A. tridentata ssp. tridentata x
A. t. ssp. vaseyana, including Fj and F2 Inbrid
generations that have been studied and con-
finned as h\brids in morphological, chemical,
and insect-host contexts (Noller and McArthur
1986, McArthur et al. 1988, 1992, Weber et al.
1994, Messina et al. 1996, Richards, Messina,
and McArthur unpublished). This hybrid com-
bination was made in an attempt to better
understand hybridization dynamics and com-
bine traits (palatabilit>, nutrient content, growth
rates) that might be favorable for large herbivore

14

Great Basin Natl iulist

[Volume 58

Tauli; 1. Ix)cation of sample colk-ctioiis. ()iiti)lantiiig sites, and saniplt- reference numbers.

TiLxon

Location and propagation inlormalion and sample reference numhei

Sri l)Y I
Artemisia tridentatu Niitt. ssp.
wijominfiensis Beetle & Young

Artemisia carta Pursh. ssp. cana

Artemisia cana Pursh. ssp. viscidiila
(Osterliout) Beetle

Study 2
Artemisia tridentata Nutt. ssp.
vaseyana (Rydb.j Beetle

Studv 3

Artemisia Iridcniiita Null. ssp.
tridentata

Arleinisia tridentata .Nutt. ss[).
vaseyana (H\cll).) Beclic

Artemisia cana Pursh. ss]). cana
Arlc)nisi<i triparlita Hydh.

Artemisia triilcniala Null. ssp.
uy(iniin^,('nsi.\ Bc<'tlc \' ^oiuig

Arco, Butte Co., 11^, W'.s.;!., October 19Sfi; grown at Sprinii\illc and
Browns Park outplanting sites

3 km S of Dinosaur, Hio Blanco Co., CO, M&S 1438; grown at Spring\ille
and Browns Park outplanting sites

Gordon Creek, 7 km W of Spring Clenn, Carbon Co., UT. W 1-019;
grown at Spring\ille and Browns Park outplanting sites

6 km N of Kemmerer, Lincoln Co., WT, M&J 1738 (U-028); grown at
Spring\ ille and Browns Park outplanting sites

1 km E of Warren, Carbon Co., MT, M&J 1743; grown at Springville and
Browns Park outplanting sites

Maybell, Moffat Co., CO, M&S 2120; grown in Shrub Sciences
Laboratory Greenhouse

Sheridan, Sheridan Co., \VY, Mo s.n., 1972, M&S 2128; grown at the
Snow Field Station

Cart Creek, Daggett Co., UT, M&B 2204

Right Fork of Hobble Creek, Utah., UT, M&S 2184, 2185; grown at
Hobble Creek and Great Basin E.xperimental Range outplanting sites, 2.V

4 km E of Salina Canyon Summit, Red Creek, Sevier Co., UT, M&S
2149; grown at Hobble Creek and Great Basin Experimental Range
outplanting sites, 2.T

7 km E of Salina Canyon Summit, Red Creek, Sevier Co., UT, M&S
2148; grown at Hobble Creek and Great Basin E.xperimental Range
outplanting sites, 4v

Pine Valley, Washington Co.. I'V. M&S 2177; grown at Hobble Creek and
Great Basin Experimental Range outplanting sites, 2.V

8 km N of St. George, E of Snows C-an\()n, Washington Co., UT, M&S
2189; grown at Hobble Creek and Great Basin Experimental Range
outplanting sites, 4.v

Tabernacle Dome, Kolol) Terrace, Zion National Park. Washington C]o., UT,
M&S 1821 A; grown at ll()l)blc Creek and Circat Basii\ I'AperinuMilal Range
outplanting sites, 2.v

4 km N of Virgin, Washington Co., UT, M&S 2191; grown at 1 lol.bic Creek
ancKlreat Basin JApiriiiK iital Range outplanting siti's, 4.v

12 km E of Dove Creek, Delores Co., CO, M&P U-076, \&Ba 22; grown at
Snow Field Station and Hobble Creek outplanting sites

Hobble Greek Canyon. I lah Co., UT, M&P U-001, M&S 147(S, 2144, 2363,
(;,\\'i,VI,L 21492; grown at I lolible Creek outplanting sites

Slicridan, Sheridan Co.. W V, \lo,v.;i.. 1972, M&S 212S; grown at the
Snow Field Shiliim

West ciilrancc, I S. Sheep Station, Dubois, Cl.ilk Co., ID; \K\S 2()S2

Paddock .3IA, F.S. Slue p Station. Dubois, ( :l,iii Co.. ID; \K\S ,s,//,,
\iigust \UUi

Ann. Butte Co., ID, \\ SIC. October 19S(i: grown .i( Si)nng\illc .iiid
Brow lis Piirk oul|)laiiling sites

(i km N of Kenunercr, Lincoln Co., W'V, M&J 1738 (U-028); grown at
Spring\ ille and Browns P;irk outplanting sites

•'Initials li)r collcclors arc B = Davi.l C. HaMxI. Ha =

Mo = .SI.plKii B. MonscM. P = A. I'lm I'lun i

Tlif V colicctioii niimlHTS refer to seed anil |ilaiit <
tlie iiiitpluntiiiK sites see iMRiire I .

Jem n. Barker. (; = Sliei.l (aMMlrieli, J = (iaiA I. jdrwiiMii. 1. = Mont E. Ixwis. .M = Iv Dnr.int Mc.\rtluir.
S = Stiwart <: Saiulerson. V = Cordon A Van K|ips, W = Urnee 1. Weleli. and Wi = Alma II Winward.
ilture aeeession niinihers in.nnlaiiii il .it llie Cleat It.isin llspeiiinenl.il K.ini;e. I'.pln.iini. I'l: l"or locations of

1998]

RAPD Analysis of Autimisia Spkciks and 1 Iviiiuns

15

Fig. 1. Locations of plant population native sites and of outplanting sites. See Table 1 for more detail. * = outplanting
sites, BP = Browns Park (Bureau of Land Management), GB = Great Basin Experimental Range (Rock> Mountain
Research Station and Manti-La Sal National Forest), HC = Hobble Creek (Utali Division of Wildlife Resources), PG =
Pleasant Grove (Uinta National Forest), SF = Snow Field Station (Rocky Moiuitain Research Station, Division of
Wildlife Resources, Snow College, and Utah State University Agricultural E.\periment Station), SP = Springville (Utah
Division of Wildlife Resources), UC — Upper Colorado Environmental Plant Center (Natmal Resources Conser\'ation
Service and Douglas and White Ri\er Soil Consenation Districts); • = 2x Atieiniiia tridcnfata ssp. la.sctjana. HC. —
Hobble Creek (M&P U-001. G,Wi,M.&L 21492, M&S 2184, 2185), KT = Kolob Tenace (M&S 1821A), PV = Pine Val-
ley (M&S 2177). SC = Salina Canyon (M&S 2149); O = 4x A. t. ssp. vaseyana, KT = Kolob Terrace (M&S 2191), PV =
Pine \'a!le\ (M&S 2189). SC = Salina Canyon (M&S 2148); ■ = Artemisia tridentata ssp. icyoininficn.sis. AR - .A.rco (W
s.„.. Oct. 1986). DI = Dinosaur (M&S 1438), GC = Gordon Creek (W U-019), KE = Kenunerer (M&J 17.38), WA =
Wanen (M&J 1743); + = Artemisia tridentata ssp. tridentata, DC = Dove Creek (M&P U-()76); A = Artemisia cana
ssp. cana, MA = Ma\bell (M&S 2120). SH = Sheridan (Mo s.n., 1972, M&S 2128); A = Artemisia cana ssp. liscidula.
CC = Cart Creek (M&B 2204); T = Artemisia tripartita. DV = U.S. Sheep Station. Dubois (M&S 2082, s.n., Aug.
1994).

con.siiinption (McArthur et al. 198S, 1992,
Weber et al. 1994). The 2nd putatixe Inhrid
coniliination is A. t. ssp. icyotningcnisis x A. tri-
partita (4 different combinations involving the
Warren, Montana, and Gordon Creek, Utah,
popnlations of A. tridentata ssp. icijoiningensis
as female parents and 2 A. tripartita popula-
tions from the entr\' snow fence and paddock

31A of the U.S. Sheep Station, Dubois, Idaho,
as pollen donors). The 3rd combination is A.
ca}ia ssp. cana x A. tridentata ssp. wyotningen-
sis (3 combinations with A. c. ssp. cana from
Sheridan, Wyoming, as the female parent and
A. t. ssp. wyoniingensis fiom Arco, Idaho, and
Kemmerer, Wyoming, as pollen donors). These
latter 2 putative hybrid combinations were

16

Great Basin Nati ralist

[Nblume 58

designed to attempt to combine tlie dronglit
tolerance of A. t. ssp. wyoniingensis with the
root-sprouting, fire-tolerant adaptation of A. c.
ssp. cana and A. tripartita (McArthur et al.
1992, McArthur 1994). Artemisia tridentata
ssp. wyo)nin<ic'nsis is not fire tolerant, and
much of its range has been usurjoed by alien
fire-adapted weed species such as Bromiis tec-
torum (McArthur et al. 1990, Monsen and
Kitchen 1994).

DNA Extraction and Amplification

We extracted DNA from indi\ idual plants
or bulked samples using a method adapted
from Delaporta et al. (1983). After the tissue
was ground to a powder in liquid nitrogen
using a mortar and pestle, about 1-1.5 ml
extraction buffer (10 niM EDTA, pH 8.00; 50
niM NaCh 100 /jlL 20% SDS and 5 aa 2 [3 mer-
captoethanol) per gram of plant tissue was
added and the mixture ground further. One-
mi portions of the homogenate were trans-
ferred to 1.5-ml centrifuge tubes and incu-
bated for 20 min at 68°C in a water bath. Fol-
lowing incubation, 500 fxh of 1 M potassium
acetate was added to each tube and the tubes
mixed thoroughly. We then incubated the sam-
ples at 4°C for 20 min. Following incubation,
the samples were centrifuged at 14,000 rpm
for 5 min. The supernatant was transferred
through micracloth to a clean microcentrifuge
tube containing 500 fiL of isopropanol. The
tubes were mixed by genth' inverting and the
samples incubated overnight at 4°C to help
precipitate the DNA (Fairbanks et al. 1993).

Because of the high amount of carbohy-
drate ol)tained after the above extraction, we
performed a carbohydrate wash (Sederhoi,
North Carolina State Universit)', Chapel Hill,
personal communication). All tubes containing
DNA from a particular plant or bulked sample
were combined to form single pellets. Each
pellet was resuspended in 700 /jlL of 1 M
NaCl and vortexed gently (DNA dissoKes in
the salt but carbohydrates do not). The sam-
ples were incubated at 4°C for 20 min and
then centrifuged at 14,000 rpm for ca 5 min.
The resulting supernatant was added 1:1 to
isopropanol and incubated overnight at 4°(> to
aid DNA precipitation. The DNA was pel-
leted and washed with 70% ethanol, dissolved
in TF (10 niM Tris, pi I 8.00; 1 niM FDTA,
pi 1 8.0j, and stored at -20°C until u.se.

DNA markers were amplified with either
AmpliTaq DNA Polymerase or AmpliTaq DNA
PoKmerase Stoffel Fragment (Perkin Elmer-
Cetus, XoiAvalk, CT). Both enz\ nies were used
to obtain different DNA bands with the same
primer because AmpliTacj tended to amplify
higher molecular weight markers than did
Stoffel Fragment (Sobral and Honevcutt 1993).
Amplifications were performed according to
Williams et al. (1990) as modified b\' Mudge et
al. (1996). Reagents for RAPD amplification
were obtained fiom Perkin Elmer-Cetus and
Promega Corp. (Madison, WI), primers from
Operon Technologies, Inc. (Alameda, CA) and
the University' of British Columbia Biotechnol-
ogy Laborator)' (Vancouver, BC). The reaction
preparation was automated b>' means of a Bio-
mek 1000 work station (Beckman Instruments
Inc., Fullerton, CA). Each sample for amplifi-
cation had a total volume of 15 (xL. Amplifica-
tions were carried out on 3 MJ Research PTC-
100 96-well thermocyclers (MJ Research Inc.,
Watertown, MA) with different programs for
AmpliTaq and Stoffel Fragment. The Ampli-
Ta(i program consisted of an initial denatura-
tion step at 92°C for 3 min, followed by 48
cycles of denaturation step at 86°C for 1 min,
36°C for 1 min 45 sec, and 72°C for 2 min.
Once the 48 cycles were complete, samples
were held at 72°C for 7 min and then stored at
4°C until electrophoresis. Minimum ramp times
were used between each step. The Stoffel Frag-
ment program consisted of an initial denatura-
tion step at 94°C for 3 min followed b> 40
cycles of 96°C for 1 sec, a 0.5°C s~' ramp to
35°C which was held for 1 sec, a 0.3°C s"!
ramp to 72°C which was held for 1 sec, and a
0.2°C s-1 ramp to 96°C. Once the 40 cycles
were complete, samples were held at 72°C for
7 min and then stored at 4'^(; until electro-
phoresis.

DXA amplification products were sepa-
rated 1)\ electrophoresis in 20 X 25- or 20 x
4()-cm 20 g L-J 1:4 Low (2%) EEO agarose:
FMC Metaphor (FMC Bioproducts, Rock-
land, ME) gels with up to 28 lanes. The entii-e
f.l-yul, sample plus 2-3 /xL of bronioiilu'uoi
blue d\(' in glycerol was added to each laiu'.
DNA size markers (pUC>-I9 207, Bios\nthesis,
Inc., Lewisxille, T\) were added to at least 2
lanes in cacli gel lor reference and i\ise in
scoring gels. SampK'S were eleetrophoresced
at 150 \ for 3 to 4 h at room temperature.

1998]

RAPD Analysis ov Artemisia Species and IhniuDs

17

Gels were stained with 0.5 /xu; ethidiuiu
hromide per nil in lioth gel and gel hnller
rliex were not destained. Gels were \isnalized
on a UV transillnniinator and photographed
with a camera s\'steni, or the\' were viewed on
a xideo imaging system that had greater resolu-
tion and storage eapahilities than photoura]")hie
methods ha\t' (Mudge et al. 199(i). Ampliricd
hands were scored and recorded as presence
or absence of bands of the same molecnlar
weight (Fig. 2). Bands of the same mobilitx
wcvv pn^snmed to be homologous.

AnaKsis of Amplified D\A Products

The NTSYS-pc statistical software package
was used to analyze coded DNA markers (Rohlf
1993). Presence or absence of specific D\A
bands (markers) was anahzed for estimating
percent similarity' with Jaccard's coefficient of
similarity- f Jaccard 1912) using XTSYS-pc, ver-
sion 1.8(). UPCiMA clusterin.g analysis (NTSYS-
pc, SAHN) and a phenetic tree (NTSYS-pc,
TREE) were generated to graphicalK' show
the percent similarit\ among appropriate sam-
ples. Phenetic trees were constructed from
indi\ idual plant data except for the Aiietnisia
tridentata ssp. wyomingensis population study.
In that study both indi\ idual plant and bulked
data were used. The l)ulked data were not
w eighted; i.e, they were treated analogously to
a single plant. Bulked samples included 5-8
indi\ idual plants.

Results

Fift>-seven primers (3-24 per study) pro-
tluced nearly 4()() (6-216 per study) scorable
markers that were used to construct similaritx
phenograms (Tables 2, 3, Figs. 3-6). The primer
and marker totals of Table 2 are not additix e
because 21 of the primers and as many as 150
of the DNA markers were shared between or
among the separate studies.

Study 1. — Figures 3 and 4 show indi\idual
plant siniilarit\ within populations of A. tri-
dentata ssj). wyomingensis, A. cana ssp. cana.
and A. c. ssp. visciduhr, among-population
similarity within each ta.xon; and similarit\
between subspecies of A. cana. These results
are within expected ranges at those systematic
levels (\'an Buren et al. 1994, Gang and Weber
1995. McArthur et al. 1998). Indi\ idual plants
within each population are generally but not

alwa>s more similar to other plants in their
own population than plants of the same taxon
in other populations.

The Gordon ('reek, L tah, and Warren, Mon-
tana, populations of A. tridentata ssp. icyoniin-
gcnsis aie less homogeneous than the other 3
pojiulations of A. t. ssp. wyoniingcnsis (Arco,
Idaho; Kcnnnerer, Wyoming; Dinosaur, Gol-
orado). liuiked samples show that the 3 geo-
graphicalK clustered populations (Dinosaur,
(Colorado; (Gordon (>reek. Utah; and Kemmerer,
Wyoming) are slightly more similar to each
another than to the more geographical!) iso-
lated populations, Arco, Idaho, and especially
Warren, Montana (Figs. 1, 3). Under the con-
ditions of our stud); indi\ idual plants within
populations were approximately 55Vc to >80%
similar in DNA markers. All populations are at
least .5()'^f similar to each other except for 1
outKing plant from Warren, Montana (Fig. 3).

The 2 populations of A. cana ssp. cana were
about 549f similar to each other, whereas
those populations were onl\' 459f similar to the
population of A. cana ssp. viscidula included in
the study (Fig. 4). The Sheridan, Wyoming,
population of A. c. ssp. cana and the Cart Creek,
Utah, population of A. c. ssp. viscidida are
more homogeneous than is the Ma\bell, Col-
orado, population of A. c. ssp. cana. The simi-
larity between A. cana subspecies is support-
ive of their conspecific affinity and placement
within the subgenus Tridentatae (McArtlun- et
al. 1998).

Study 2. — Comparisons of the 2.v and 4.v
populations of A. tridentata ssp. vascyana are
presented in the Figure 4 phenogram as indi-
vidual plants. In general, as in stud\ 1. indi-
\'idual plants for each population clustered on
the same stem. All plants and populations for
this subspecies were >509f similar as was the
case for plants and populations within sub-
species in stud\ 1. Results reveal 4 groups
with >559c siniilarit\' (Fig. 5): the top one com-
prises the 11 Salina Can>on (Utah) Ix plants,
16 of the 21 Hobble Creek (Utah) 2.v plants,
and 1 of the 11 Kolob Terrace (Utah) 4v plants;
the 2nd group is composed of all 8 Pine Valley
(Utah) 2.V plants, all 12 Pine Valle\ 4.v plants,
and 11 of the 12 Kolob Tenace 2.v plants; the
3rd one is composed of the 9 Salina Canyon 4x
plants, 5 of the 21 Hobble Creek 2.V plants, and
1 Kolob Terrace 4.v plant: the bottom group
comprises 9 of the 1 1 Kolob Terrace 4v plants
and a single Kolob Terrace 2x plant. These

18

Great Basin Naturalist

[Volume 58

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Artemisia tridentata ssp. vaseyana

Fiy. 2. I^li()l()i;ia|)lis of yt'ls: toj), jjliDtoiirapli nl Arti'iiiisin ((iiiii siil)siK'ci('S (ijcl I lU .' 2Soi; hotlcnn pliotouiaiili ol
Artemisia tridentata ssj). laseijana 2.v and 4.v populations ironi Salina C.'anNon (jicl 598). IViplicalc planl samples arc in
laiifs lahflfd 01, 02. rtc; niolfciilar nuirktT lanes (pUC-iy 207) arc laln-lcci.

results arc coiisislcnl \\il!i u;c()u;rapliic' scpaia- llic ls( and '1\\(\ groups, 3.1' ^ siinilai', arc 2.v

tion (Fig. 1) except (or 2 Kolol) Terrace 4.v witli (lie exception ol tlic l.v Tine \allc\ plants

plants that are in tin- 1st aud third j^roups, and a siiiiile h Kolol) Icrracc planl, wlu-rcas the

respectively, rather than the 4th ji;r()up (JMji;. 5). 3rd and 4th j:;roups, oA7c similar, are primarilx

1998] RAPD Analysis n\- Aiuimisia Spkciks wd I Imuuds 19

Tabi i: 2. Number of prinuTS aiul DNA marker hands used in separate studies.

Stndv

No. of
primers

No. of
hands

Primer sonrees'

Sn O"! 1

Artniii.'iid Iridtiitatu ssp. uijoiniii^cusi.s popnlations
Arti'ini.sid ((iiui snlispeeies

Sti nv 2

Arhitii'iid tridiiiliita ssji. id.si'ijdiid. 2.v and 4.v

Sti ov 3

Aiietni.sid Iridculdtd ssp. IridfuUitd x A. t. ssp.

vascijand
Artemisia tridtiitdtd ssji. uiioiiiinf^cnsis x A.

tni)aiiita
Artctni-sia cdtui ssp. cdna x A. Iiidcntald

ssp. wyomin^cnsis

22''
24'

14d

IP

4f

3'^

149
216

133

19
15

6

Operon. UBC
Olieroii, L BC

UBC

Operon
Operon, UBC
Operon, UBC

■KJperon = Opcmii Trclmolonit's. Inc., L BC = Liiivcrsitv ol British Columbia Biotechnology Laliorutory.

''OPH-12. OP.\I"-(Kv ()P.\P-()1, OP.\P-03, .VPOR-Oa, AP.'\\V-()4. UBC-2()8, UBC-275, UBC-285, UBC-302, UBC-34.5, UBC-356, UBC:-.3.5S,

UBC-413, UB(:-421, L'BC-425. UBC-456, UBC-769, UBC-TTO, UBC-772

cOP.\P-01. OP.\P-07, OP.W-tM, UBC-20S, UBC-27(). UBC-2a5, UBC-302, UBC-.341, UBC-.356, UBC-3.5S, l'BC-.361, UBC-413. UBC-421.

UBC-.542. UBC-.571. UBC-.584, UBC-.585, UBC-595, UBC-59S, UBC-769. UBC-770, UBC-772

''See Table 3.

eOPF-19, OPJ-04. OPU-03. OPU-17. OP\\-07. OPW-OS. ()l>\\-17, C)P.\.12, OPV-Ol. OPV-02. OPV-10

fUBC-208. UBC-28.5. UBC-358. UBC-425

cOP.\P-()l. lBC-241. rBC-24.5

UBC-,361, UBC-409.
UBC-.534. UBC-.5.36,

T.\BL,E 3. Primer name, sequence, and numlier of markers
generated from each primer used for amplification of sam-
ple l).N.\ lor stud)- 2 (2.V and 4v Aiicinisid tridoitdtd ssp.
lasci/diid populations.

Numher

Primer nanie^

Primer sequence (5 '-^3')

of markers

UBC-157

CGTGGGCAGG

11

UBC- 180

GGGCCACGCT

12

UBC-199

GCTCCCCCAC

12

UBC -457

CGACGCCCTG

5

UBC -459

GCGTCGAGGG

8

UBC-515

GGGGGCCTCA

10

UBC-540

CGGACCGCGT

9

UBC-542

CCCATGGCCC

9

UBC-563

CGCCGCTCCT

(

UBC-584

GCGGGCAGGA

16

UBC-592

GGGCGAGTCC

5

UBC-59S

ACGGGCGCTC

10

UBC-601

CCGCCCACTG

10

UBC -6 15

CGTCGAGCGG

9

■'UiiiMrMly of British Columbia Biotechnology Laboratory, \'.iir(

4.V witli the exception of 5 Hol^ble C'reek and 1
Kolob Terrace 2.v plants.

STUr:)V 3. — D\A marker similarities amony
the putative hybrid plants and their parents
are illustrated in Figure 6. The 1st hybiid com-
bination (A. tridentata ssp. tridentata x A. t.
ssp. vascyana). which had been confirmed by
pre\ ious studies (McArthur et al. 1988, Weber
et al. 1994, Messina et al. 1996), yielded 3
major groups plus sexeral outliers (Fig. 6). The

major groups are the A. tridentata ssp. vase-
ijana parent (top), the F^ and F2 hybrids (cen-
ter), and the A. t. ssp. tridentata parent (near
bottom). The outliers are some A. t. ssp. tri-
dentata parent plants and especially F2 plants
(near bottom of top group and near bottom).
These results of a parent through Fo hxlirid
generations gi\'e evidence of h>l)ridization.
The parent plants are well separated in the
phenogram (Fig. 6). The Fj and F2 plants are
closer to the maternal parent than expected.
F2 h\brids do, however, show additional seg-
regation over the F^ plants as expected (Fig.
6). Similarity values of Figure 6 are less than
others presented herein and in McArthur et
al. (1998) because we worked with taxon-spe-
cific markers to the extent that we could find
them; therefore the values should be consid-
ered relative and not absolute. The other 2
putative hybrid combinations (A. tridenata
ssp. wyomingensis x A. tripartita and A. cana
ssp. cana x A. tridentata ssp. wyomingensis)
gave contrasting results (data not shown). The
A. tridentata ssp. wyomingensis x A. tripartita
combination was not successful. All female
parent plants (A' = 10), progeny of self-polli-
nated control plants {N = 7), and putative
h\brid plants (N = 15) clustered in 1 stem
above 50% similarity, whereas pollen parents
(2 different A. tripaiiita populations, each N =
6 ) clustered in a separate group above 40%
similarit)-. The 2 groups are only about 22%

20

Great Basin Nati kalis r

[X'olume 58

0.70

^

Arco

ndividual plant 019

Arco

ndividual plant 060

Arco

ndividual plant 091

Arco

ndividual plant 072

Arco

bulk sample

Arco

ndividual plant 131

Gordc

n Creek individual plant

059

Gordon Creek individual plant

070

Gordon Creek individual plant

093

Dinos

aur individual plant 001

Dines

aur individual plant 004

Dinos

aur individual plant 002

Dinos

aur individual plant 003

Dinos

aur bulk sample

Dinos

aur individual plant 005

Kemn

lerer individual plant 005

Gord

m Creek individual plant

001

Gord

3n Creek bulk sample

Gord

Dn Creek individual plant

002

Gord

Dn Creek individual plant

003

Kemn

rterer individual plant 115

Kemn

nerer individual plant 16C

Kemn

nerer bulk sample

Kemn

nerer individual plant 07

Kemn

nercr individual plant 144

Warr

en individual plant 141

Warren individual plant 199

Warren individual plant 047

Warr

en individual plant 109

Warr

en bulk sample

Gord

Dn Creek individual plant

079

Gordon Creek individual plant

139

Warren individual plant 057

FiK- 3. I'lieiiosiiain iJiodiiccd iisiiitj UPCMA cliisti'iiny; aiial\ sis (NTS'^'S-pc, Rohll 1993) tor 5 Arlciiiisid Iriilcntdla ssp.
uiii>iui)i<^('nsifi populations. Iii(li\ idiial ])Iaiits and hulked samples arc iiulnded.

.similar. The A. cann ssp. raua x A. tridcntata
ssp. wyoinin^ciisis conihination, on the otluT
hand, yielded results that had several putati\t'
lu'hrid plants intermediate in similarity to the
2 parental stoeks. 'I'hese resnlts are corrobo-
rated, in part, by eytoloj^ieal studies. The A.
cana ssp. cana x A. tridcntata ssp. wi/()inin<^('u-
sis combination yielded (ix plants, which would
be expected in an S.v (A. cana ssp. cana) x 4.v
(A. tridcntata ssp. wyoniiii^cnsis) combination.
Because both A. tridentata ssp. uij()niin<:,cnsis
and A. tripartita are 4.v, c\ t()l()u;ieal results are
not instructixc in that eombinalioii. Meiolie
liUures of this combination displax iimiieroiis
nuiltivalcnts, especialK <|uadri\alenls, .is did
A. tridcntata ssp. W{/<>niin<icnsis plants and
other jiolyploid taxa in an earlier i\ (()I()u;ieal
study (McArthuretal. 1981).

Discussion

Use ok IL-VPD markers. — The set of stud-
ies reported herein adds wciuht to \hc e\i-
dence that KAFD markers are iistiul in s\s-
tematic problems at \arious hierarchical lexels
from indix idual plants to genera (e.g., Le\ i et
al. 1993, Santos et al. 1994, Van Buren c-t al.
1994, (iang and Weber 1995, McArthur et al.
1998) and in hybiidi/ation probK-ms inelutling
hybrid zones and natural and artificial Inbrid-
i/ations (e.g., linen and llelentjaris 1993, Brad-
shaw et al. 1994, Kennard cl al. 1994, I>an and
.Arnold 199(1 Lin and Kitiaiid I99(i. \liidge et
al. 199(i).

(IiAiriic difI'Kriah \ri()\ \r xahiois svs-
II.MAIIC l,i;\ i:i.s. — Tlu" amount of genetic dil-
leii'iitiation among indixidual plants within

1998]

liVl'D Analysis ov Aihemisia Sfkc:ii-:s and IIiuiuds

21

Sheridan 1
Shtridan 2
Sheridan 3
Sheridan 5

Shendjn 4
MayhcU 2
MavbeU 3
Maybcll 4
Maybell 1
Maybell 5
Cart Creek 1
Cart Creek 5
Cart Creek 3
Cart Creek 4
Cart Creek 2

Fig. 4. PluMiogram produced using UPCMA clustering
analysis (NTSYS-pc, Rohlf 1993) for Arlonisia cana sub-
species and populations. Indi\idual plants are as follows:
A. cana ssp. cana, Sheridan (indixidual plants 1-5), May-
hell (individual plants 1-5); A. cana ssp. liscidtila. Cart
Creek (indi\idual plants 1-5).

population.s as revealed by genomic DNA
markers in this set of studies (Figs. 3-6) is sim-
ilar to that of populations determined by
bulked samples (Fig. 3; Van Buren et al. 1994,
Gang and Weber 1995, McArthur et al. in
re\ie\\). Similarit)' bet\veen indi\idiuil plants
within populations is usuall\- in the range of
50-85%. An exception is in the A. tridentata
ssp. tridentata x A. t. ssp. vaseijana hybridiza-
tion stud) (Fig. 6), where fewer subspecies
contrasting markers were used and similarity
in h\brid and parental plants ranges from 20%
to 100% Most plants within populations of that
stud) are above 50% in similaritx, but several
outliers are onK- about 20-25% similar to
other plants in their populations.

We suspect that indix idual plants are as dif-
ferent from one another within closeK' spaced
populations as populations within ta.xa are
from one another because of the wind-polli-
nated nature of the Tridentatae (McArthur et
al. 1979, 1988, McArthur 1989). In a wind-pol-
lination s\stem, pollen of landscape-dominant
plants is dispersed not only within populations
l)ut also between populations (Grant 1975,

Franklin 1981, McArthur 1989). Fiuthere\i-
(lence of the spread of Tridoitatac pollen is
that dining its fall pollination season, Triden-
tatae {= sagebrush) pollen counts are given
out by weather reporters to the public in areas
removed from stands of plants for the benefit
of those allergic to Tridentatae pollen.

Subspecies range from 25% (A. tridentata:
see Fig. 6) to 45% (A. cana\ see Fig. 4) similar-
ity among populations, which is generalK
more similar than the between-species simi-
larities reported in the genera Ranunculus,
Artemisia, and Sphaeroneria except for closeK
related (usualK- within same subgenus) species
(Van Bin-en et al. 1994, McArthur et al. 1998).
The 25% value may be low because DNA
markers were selected to contrast the sub-
species. Between-genera similarity values in a
companion studx' (McArthur et al. 1998) were
also lower, 7-18%.

De xovo oricin of 4a' A. tridextata SSI'.
\'AS£yAA'A. — Cytological evidence (kar>'otypic
structure and high multixalent freciuencies in
pohploids) suggests that the Tridentatae include
a high frequencey of autopoKploidy (McAithur
et al. 1981). DNA marker data (Fig. 5) are use-
ful in addressing the h>pothesis that 4x popu-
lations and plants that are adjacent or inter-
mixed with 2.V populations ma\' be of de novo,
in situ origin. Data suggest that the hypothesis
is at least partialK correct. The 4.v plants from
near Pine Valle>- fall within the same grouping
as the nearby 2x plants from Pine Valley and
Kolob Terrace (Fig. 5). We suggest that these
4.V plants are of de novo origin from the local
2.V population(s). Gytological evidence gives
additional credence to this hypothesis as we
ha\e located 3 populations in the Pine Valley
area that are indistinguishable morphologically
and chemicalK (coumarin compound content)
but contain individual 2.v and 4.v plants
(McArthur and Sanderson in review). Since
the other 4.v populations (Salina Can>'on and
Kolob Terrace) did not cluster tighdy with
adjacent 2x populations, the\' ma\' not be recent
autoploids. However, our studies show that all
sampled A. tridentata ssp. vaseijana plants are
(luite similar (above 50%; see Fig. 5), suggest-
ing earlier or more distant autopolyploidy as
the source of 4.v populations. These 4v popula-
tions have apparentK dispersed, given the
evident intertwining DNA marker (Fig. 5)
and geographic patterns (Fig. 1). Recently,

22

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li\PU A.\Ai,vsis (.n- AiULMisiA Si'ix;ii:s and IIvbkids

23

aiitojioK pIoicK li;is Ix'cii i('f()'j;iii/.i'(l as pla\iiiu;
a luoic iiiipoilaiil lolc in cn oliitioii in a w icK'
ai"ra\ ol plant spctirs than lias hccn tiadition-
all\ ifc()Uni/,c(l, e.,U., Snuill UJS.l, Ba\cT 19S7,
Ness et al. 1989, Lumaret ft al. 1989, \an Dijk
et al. 1992, Soltis and Soltis 1993, Bretagnolle
and Tlionipson 199(i, Lausliinan et al. 1996.
\\t' l)clir\i' IIk' (lata wc present here gi\'e fur-
ther eredence to the iniportanee ol antopolx-
ploicK in Thdcntatac.

IIAPD CONTl^IBL'TION TO IIVBKIDI/, A IK )\
Ml nil s |\ TniDEMATAE. — The 7)-/<-/r'/i/c//^/(' are
thought to ha\e e\oKed throui^h a pattein ol
u;eogi'aphic migration, introgression, and hxhrid-
i/ation (Ward 1953. Beetle 1960, Hanks et al.
1973. Me.Vrthurand Plunnner 1978, McArthnr
et al. 1981, 1988, Thompson 1991). Therefore,
stndies that eontribute to the nnderstanding of
hxhridization processes in the gronp are needed
to hotter understand the gronp s d\ namic pop-
ulation l)iolog\ and e\olution. Our D\A marker
data are from 3 different Inbrid combinations.
These data confirm the hybrid nature of the A.
tridcntata ssp. tvidentata X A. t. ssp. vaseyana
prom'UN pre\ionslv studied b\- other techniques
( .McArdiur et al. 1988, 1992, Weber et al. 1994,
Messina et al. 1996). The segregation of RAPD
markers in Fj and F-, generations is a pattern
that can be explained as the consequence ol
Inbrid segregation (Fig. 6). Our data also sup-
port a successful h\bridization of the A. cana
ssp. cana x A. tridcntata ssp. wyotningcnsis
combination. Seven of the 13 putative hybrid
plants examined for FL\PD markers are inter-
mediate in marker patterns in respect to their
parents, whereas 6 are similar to the maternal
parent. These results are consistent with our
prexious results on h\bridizati()n wherein sub-
stantix (.' fractions of the progen\' ol successful
Inbiid combinations are indeed of hybrid ori-
gin and other substantixe fractions are the re-
sult of self-pollinations (McArthur et al. 1988).
The other h\brid combination, A. tridcntata ssp.
ui/(>inin<i.cn.sis x A. tyi])art\ta. was not success-

Fig. 5 (.see facing page). Phenograin produced using
UPGMA clustering analysis (\TSY.S-pc, Holilf 1993) for
Artemisia tridcntata ssp. vaseyana 2x and 4.v populations.
Individual plants are ke\ed as follows: 2.V = di])loid, 4.v —
tetraploid, IIC = Hobble Creek. KT = Kolob Terrace, P\'
= Pine \'alley, SC = Salina Can\()n. See Figure 1 and
Table 1 for more detailed location information. Circled
niunbers, e.g., ®, are the major groups discussed in the
text.

Inl. All putatix'e Inbrid progen\- are similar to
tluMr maternal parents.

iliese hybrid combinations, aside liom help-
ing us better understand Tridcntatac breeding
s\stems, were made for specific purposes
(McArthur et al. 1985, 1988, 1992, McArthur
1988). The A. tridcntata ssp. tridcntata x A. /.
ssp. vaseyana combination has been extended
to the F, generation with the goal of maintain-
ing the growth and wood) biomass character-
istics ol the paternal pari'ut and the leafiness
and palatabilit) (= essential oil profile) to large
ungulates of the maternal parent. We are cur-
rently evaluating those characteristics as well
as the adaptation of the hybrids with respect
to parental stock (Noller and McArthur 1986,
McArthur et al. 1988, Weber et al. 1994,
Messina et al. 1996, McArthur unpublished).
The other 2 Inbrids were made to combine
the drought tolerance and widespread adapt-
abilitx of the landscape-dominant A. tridcntata
ssp. wyomingcni.s with the root-sprouting, fire-
tolerance capabilities of A. cana ssp. cana or
A. tripartita (Beede 1960, McArthur 1994).
Much of die natin-al range of A. tridcntata ssp.
wyoinin^cn.sis has been lost to cheatgrass and
other alien fire-tolerant annuiil weeds (McArthur
et al. 1990, Monsen and Kitchen 1994). The
successful Fy Inbrids have been outplanted
and are apparentK' fertile (we recenth col-
lected filled seed). Additional evaluation of both
successful hybrid lines is necessary before they
can be considered for wide-scale planting.
Morever, the use of such material should be
critically evaluated by land managers and oth-
ers with interest in the well-being of our land-
scapes.

We ha\e discussed some traits in Tridcn-
tatac species and h>brids that might be desir-
able to combine. The location of such traits on
a genetic map would be useful information.
RAPD, in concert w ith other molecular genetic
tools and additional hyl)rid stock, could be
used to document chromosomal locations as
has been done with other plants, e.g., Penner
et al. 1993, Bradshaw et al. 1994, Kennard et
al. 1994. Santos et al. 1994, 1995. Mudge et al.
1996. Such information would also be useful
in the ongoing work of understanding the
d\namics of h\l)rid zones between the sub-
species of A. tridcntata (McArthur et al. 1988,
Freeman et al. 1991, 1995, Weber et al. 1994,
Graham et al. 1995, Messina et al. 1996, Wang
et al. 1997).

24

(iREAT Basin Naturalist

[Volume 58

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' 1

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1998]

HAPI) Awi.vsis ()i-.\/f/7:.\//.s/.A Si'ix.iKs and IIvbiuds

25

Viii,. 6 (see facing page). Plienograni procliicecl iisinu;
I P{;MA clustering anai\sis (\TSYS-pc, Kolill' 1993) for
Artemisia tridcntata ssp. thdcntata x A. t. ssp. va.sci/aiHi
inclncling parental and F| and Vi plant populations. Indi-
\idnal plants ari' ke\ed as follows: DC — A. t. ssp. tridiit-
tuta parent plant (Do\e Cheek), HC = A. t. ssp. vasi'ijaiKi
parent plant (Hobble Creek), F] = 1st generation lixiirid
plant, F.5 = 2nd generation Inbrid jilant. Carded ninii-
licrs, e.g. (D, are the major groups disensscd in the te.\t.

ACKXOWLEDCMEXTS

F.Miliiation of plant materials was made pos-
sible 1)\ the uenerous cooperation of se\eral
landowners inckiding the USDA Forest Ser-
\ ice Uinta. Manti-La Sal, Ashley, Fishlake, and
Dixie National Forests; Utah Department of
Natural Resources, Utah Di\'ision of Wildlife
Resources (Pittman-Robertson Agreement W-
82-R); USDI Bureau of Land Management;
Snow Field Station (Roek\ Nh)nntain Research
Station, Utah Di\ ision of Wildlife Resources,
Snow College, and Utah State University Agri-
cultural E.xperiment Station cooperating); Upper
(Colorado En\ ironmental Plant Center (USDA
Natural Resources Conser\ation Service and
White River and Douglas Soil Conservation
Districts cooperating); and USDA Agricultural
Research Seivice, U.S. Sheep Station. The work
was partial!) funded b>" U.S. Department of
Agriculture CSREES competitive grant 91-
98300-6157 and by cooperative agreement
INT-95013 RJVA between the Rocky Moun-
tain Research Station (formerK' Intermountain
Research Station) and Brigham 'i'oung Univer-
sity'. We thank Paul Evans, Kim Haiper, Can
Jorgensen, Steve Monsen, Dw^ain Nelson, Jeff
Ott, Richard Stevens, Julie Tolman, John
Walker, and Bruce Welch for assistance with
\ arious parts of this work. Clyde Blauer, G.K.
Brown, Carl Freeman, Leila Shultz, and an
anonxnious re\iewer pro\ided helpful re\"iews
of an earlier draft of the manuscript. The use
of trade or firm names in this paper is for
reader information and does not impK' en-
dorsement b\ the U.S. Department of Agricul-
ture of an\ product or serxice.

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1998]

RAPD Anaiasis oi- A«77:.\//.s/.\ Spkciks and Hvhkids

27

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Received 19 March 1997
Accepted 28 August 1997

Great Basin Naturalist 58(1), © 1998, pp. 28-;37

BITTERBRUSH {PURSHIA TRIDENTATA PURSHj
GROWTH IN RELATION TO BROWSING

Carl L. \\aiuh()lt>, W. Wyatt Fraas". and Micliael R. Frisina2

AbstR-ACT. — The objectives of this study ucrf to compare vegetative and reproductive growth characters of bitter-
brush (Purshia tridentata Pursh) stands as they relate to browsing levels. Growth characters were measured on 10 eco-
logically diverse stands in southwestern Montana on which browsing ranged from 0% to 60% of all current annual long
shoot (LS) growth. Bitterbrush plants exhibited both twig-level and plant-level responses to browsing. Total bud densit)-
per plant was similar for browsed and imbrowsed sites, but differed {P < 0.01) between browsed and unbrowsed twigs.
Browsed twigs produced one-half the leaf cluster densitx" produced b\- unbrowsed hvigs. No significant (P < 0.0.5) rela-
tionship between browsing levels on browsed plants and bud densities was found. Length of old-growth twigs per plant
was shorter (P < 0.001) on browsed sites than on unbrowsed sites. Binning at 2 en\'ironmentall\' paired sites reduced
flower bud density {P < 0.001) 9 and 10 growing seasons later although LS length was not affected. Growth of LS
showed a site-by-year interaction (P < 0.05). Oiu" data suggest that long-term imbrowsed plants should not be used as a
standard for comparison with normally browsed plants.

Key words: Purshia tridentata, hittcrliritsh. hrousing, shoot growth, hud decclopinciU. Montana.

Antelope bitterbrush {Purshia tridentata
Pursh), well documented as a valuable food
source for big-game animals (Kufeld 1973,
Kufeld et al. 1973), is highly palatable, moder-
ately nutritious, and common on many big-
game winter ranges (Giunta et al. 1978), al-
though it seems to be declining in some areas
(Winward and Findley 1983). Bitterbrush is
found in a wide range of habitats (Franklin and
Dyrness 1973) and is useful as a ground stabi-
lizer on exposed soils (Nord 1959). Therefore,
land managers are interested in its propaga-
tion, growth, and management to improve de-
graded wildlife habitat.

Known for its variability in habitat, mor-
phology, and physiology, bitterbrush ranges
from prostrate forms only 10 cm high to colmn-
nar forms over 3 m tall (Winward and Findley
1983). Color, shape, and size of leaves, stems,
and seeds vary between and within popula-
tions (Alderfer 1977). Mowing and burning
result in responses that range from death to
vigorous sprouting ((^lark et al. 1982). \\ Iiile
these adaptations enable bitteibnisli to inhabit
widely divergent habitats in western Norlli
America, they can also make management of
the species more dillicult unless the resi)()nsc
of local populations is known.

Guenther (1989) studied the environmental
relationships of bitterbrush stands on Montana
Fish, Wildlife, and Parks' Mount Haggin \\'ild-
life Management Area (MHWMA) in south-
western Montana and noted the wide range of
habitats and stand growth. Guenther (1989)
also found a high le\'el of browsing on bitter-
brush plants and little successful reproduction
during the previous decade. Wambolt et al.
(1996) compared some of the same MH\\'MA
sites with 5 other southwestern Montana loca-
tions and found differences in crude protein
content by' site.

The specific objectixes of this stucK wtMC to
compare \egetative and repioductixe growth
characters of 10 bitterbrush stands on and
near the MHWMA and to relate them to
browsing levels. We hypothesized that plants
from nearby bitterbrush stands art' not uiii-
fonn in their grow th characteristics.

Mi; I HODS
Slud\ -Sites

We chose 10 stucK sites primariK to repre-
sent bitterbrush stands lioiii a langc of t'lni-
lonmental conditions (Table 1). ineliidi'd wt-re a
burned site and sites protected from browsing.

'Dcpurtiiieiit orAiiiiiiul and HaiiKc .Sciciici's, Montana Stutc UniviMsit\, Hn/cni.in. MT.'iMTlT
^Montana Dt-parlnienl oll'isli. Wildliff. and I'ark.s. Butlf, MT .59701

28

1998]

Bl'ITEHBHLSH GkoW I

29

All sites are located within a radius of 14.5 km
near Butte and Anaconda in southwestern
Montana. Lonu-terni climatic iccords were
a\ailal)le for the <j;eneral stud\ area from the
Anaconda weather station at 1700 m ele\ation.
Annual precipitation at Anaconda a\erages
340 mm, with 47'7r received between April
and July (\0.\.A 1991).

Negetation t\ pes at all but 3 sites (Burn,
Unburn, and iliuh Rye) are serai stai!;es of the
bitterbrush-bluebunch wheatgrass {Agropyroii
spicatum Pursh) habitat t>pe (Mueggler and
.Stewart 1980). The dominant shrub is bitter-
I)rush, but understor)' vegetation is regressed
priniariK from grazing (Fraas et al. 1992) on
the other 7 sites from the described potential
clima.\ composition (Youtie et al. 1988).

We selected the Butte site at Maude S Can-
\()n, near Butte, Montana, because it receives
no ungulate browsing. The plant communit\'
consists of bitterbrush, Centaurea maculosa
Lam. (spotted knapweed), RiJ)e.s cercwn Dougl.
(scjuaw currant), and Rosa woodsii Lindl.
(Woods rose).

At D\y Cottonwood Creek in the Deerlodge
district of the Deerlodge National Forest, we
studied a 2-part e.xclosure. One portion, k-nowii
as the Deer exclosure, was game proof The
other half allowed deer use but served as a
li\ estock e.xclosure and thus was known as the
(>attle e.xclosure. Near the e.xclosure, we studied
a bitterbrush stand known as the Cattle + Deer
site because it sustained both cattle and mule
deer browsing. These 3 sites ha\e a scattered
{)\erstory of Pseudotsuga menziesii [Mirb.]
Franco (Douglas-fir). A large number of native
perennial forbs occur in the understory on
these sites.

To gauge the impacts of burning bitterbrush
in southwestern Montana, we selected 2 sites.
These sites (Bum, Unburn) were environmen-
talK paired on both sides of a burn line on the
south flank of Steep Mountain, 8 km northwest
of Butte, in the Butte district of the Deerlodge
National Forest. The plant community' on these
2 sites is a bitterlirush-mountain big sagebnish
{Artemisia iridcntata Nutt. ssp. vaseijana [R\db.]
Beetle)-bluebunch wheatgrass association inter-
mediate to die big sagebrush-bluebunch wheat-
grass and bitterbrush-bluebunch wheatgrass
habitat t\pes of Mueggler and Stewart (1980).
The prescribed burn was conducted 3 No\ em-
ber 1981 after a year's rest from livestock graz-
ing on both sites to increase fuel loads. Li\e-

TABLt; 1. Topographic characteri.stics of the 10 study sites.
Data from the last 4 sites were obtained from Gueiither

(1989).

l-',le\ati()n

.Slope

.Aspect

Site

(inj

{%)

(°)

Butte

1730

26

234

Deer e.xclosure

1830

12

225

Cattle e.xclosure

1830

16

188

Cattle + Deer

1820

10

190

Bum

2010

22

200

Unburn

2010

22

200

Powerline

1640

16

S.5

W illow Creek

17S0

31

110

l-lailroad C.ulch

1650

32

115

High f^\e

1940

38

120

stock use on both sites resinned 15 September
1982.

Four sites were located on the MllWMA,
owned and managed by Montana Fish, Wildlife,
and Parks. The Powerline site is on a slope 50
m above a perennial stream on the northeast
edge of the MHWMA big-game winter range.
The plant community consists of bitterbrush
and spotted knapweed. The Willow Creek site,
near the top of a grassy ridge 150 m above
Willow Creek, supports a relatively large
amount of Ehjmus cinereus Scribn. & Merr.
(basin wild r\e), along with other perennial
grasses and bitterbrush. This area was used as
winter range by mule deer, elk, and moose.
The Railroad Gulch site is also on the deer
and elk winter range. This site occupies a mid-
slope position 30 m above an intermittent
stream, where the plant community' consists of
bitterbrush and spotted knapweed. The High
Rye site, 1500 m higher in elevation than the
other MHWMA sites, appears to receive the
greatest snowpack. The plant community on
the High Rye site is typical of the bitter-
brush-rough fescue {Festiica scabrella Torre>
ex Hook.) habitat type (Mueggler and Stewart
1980), with those species ciuTentK- dominant.
Guenther (1989) found the least amount of
big-game use at this location among the 4
MHWMA sites. The MHWMA study sites re-
cei\ed insignificant lc\cls of livestock grazing.

Sampling and AnaKses

Stud\ sites typical of their communities were
delineated b\ five 15-m transect lines placed
perpendicular to the slope at 3-m intervals,
thus comprising a study plot of 15 x 12 m. We

30

Great Basin Natlfl\list

[Volume 58

recorded topo,uraphic information at each site,
determining aspect by taking a compass bear-
ing from the major sk)pe, measuring slope
with a clinometer, and ascertaining elexation
from USGS topographic maps. The informa-
tion from MHWMA sites was taken from
Cuenther (1989).

We used the following definitions during
the stud\': bitterbrush plant — a single stem or
group of stems with a single point of origin;
leaf cluster — a bud which had produced a
group of lea\es and which had not elongated
(<7 mm in length); long shoot (LS) — a bud
structure that had elongated (>7 mm in length)
in the current growing season and consisted of
a stem and attached leaf clusters; flower — a
bud which had produced a flower; flowers
grew only on 1-yr-old or older stems.

Two bitterbrush plants rooted within 1 m of
each transect line were randomly selected for
measurements (10 plants per site). We ran-
domly chose 4 branches on each plant using a
frame with 10-cm grids placed on top of the
plant. Random numbers identified grid inter-
sections. The closest live branch to a plumb
line dropped through the grid was sampled.
On each sampled branch we recorded the fol-
lowing: age and length of each stem segment,
length of LS, number of flowers, leaf clusters,
and LS. Apical bud status of each terminal LS
segment was recorded as browsed (within the
past year), imbrowsed, or dead. Flowers were
counted in early July, and leaf clusters and LS
were counted and measured in early Septem-
ber. We compared measurements only from
branch (LS) segments <3 yr old, as little bud
acti\it\' occurred on older portions of the
branches, 'lb determine age, we examined
annual growth scars after an initial trial of
comparing growth scars with growth rings.
These measurements were sunnnari/ed across
all 4 branches sampled per plant to create a
plant average for each categorx; Oxcrall aver-
ages resulted from averaging the 10 jilant
averages for each of the 10 stnd\ sites (100
plants).

We observed each sampled branch lot
browsing use during the previous winter,
(iuenther (1989) found a high correlation (/■ =
0.94, I' < 0.0001) in measuring percent bitter-
brush utilization 1)\ determining eithei" per-
centage of LS browsed or length of LS re-
moved; thus, we determined the perci'iitage of
total LS browsed. All branches were consid-

ered, regardless ol a\ailal)ilit\ to browsers, to
determine plant response to remo\ al of a per-
centage of total annual growth to relate to pre-
viously recommended use le\els (Honnax 1943,
Garrison 1953, Martinsen 1960, Lay 1965,
Unless and Jensen 1983). Browsing-le\'el analy-
ses were conducted by comparing the number
of browsed and unbrowsed lixe LS on each
plant in the manner detailed b\' Wambolt
(1996). Browsed and unbrowsed twigs on a
plant were each pooled across branches for
comparison of browsing response on a plant
level. By combining plant averages we then
created averages for the 10 sites.

Occurrence of unequal variances for com-
parisons, as experienced by Bilbrough (1990)
with similar data, required use ol nonparamet-
ric statistical tests (Sokal and Rohlf 1981): a
Wilcoxon signed-rank test (Snedecor and
Cochran 1989) for comparison of paired mea-
sures (such as the same plants between xears),
and a Mann-Whitney rank-sum test (Snedecor
and Cochran 1989) for comparison of group
means, both at P < 0.05. Interactions between
years, sites, and treatments were anal\ zed with
a multi-factor analysis of variance (Snedecor
and Cochran 1989). Correlation was used to
measure the relationship between some vari-
ables without a dependence relationship
(Snedecor and Cochran 1989). Comparisons
between sites were based on least significant
difference (LSD; Snedecor and Cochran 1989)
at F < 0.05. Least significant differences were
calculated as part of the anaKsis of \'ariance
for pairs of means, such as site-to-site or \'ear-
to-year comparisons. All statistical tests were
programs of the MSUSTVT statistical program
(Lund 1991).

Rksuits am:) Discrssiox
Browsing Effects

At the S browsed sites the browsing le\i-I
ranged from 23% to 60% remox al of all eur-
rent annual LS (Table 2). This range was with-
in prexiously recommended le\els for long-
term health and maintenance of stands (llor-
nia\ 1943, Garrison 1953, Steinhoff 1959, Mar-
tinsen 19()0, Lay 1965, Shepherd 1971). Only
2 sites had less browsing the 2nd winter {P <
0.05), while the other 6 were browsed at
nearK the same le\el both xcars. During 1990
the S sites wi-re c>(iuall\ browsed, but in 1991
some \ariation in browsing le\els oeeurretl

1998]

BriTKHBlUSII CiHOW 111

31

Table 2. Browsing Itnel (percent) for 1990 and 1991 at
tlic stuck sites, based on nimiher of total lonj; shoots (LS)
reni()\ I'd.

Site

1990

1991

Butte

(y'-^-

()../

Deer exclosure

Otx

Qay.

Cattle exclosure

45a«

39awxy

Cattle + Deer

55"*

54'«y

Bum

48aw

5(>«>

Unburn

51aw

ei^'y

Powerline

51aw

4Qawxy

Willow Creek

52''«

23bw

Railroad Gulch

53«*

37a«-x>

High R>e

fi()aw

3()l,wx

'Ro« entries «ith similar lowercase letters (ab) are not signifieaiitK diflerent
(Wilcoxon test. P < 0.0,5).

-Column entries with similar lowercase letters (wxyz) are not sigiuficantly dif-
ferent (LSD. />< 0.05).

among .sites. Exaluation of hrowsing effects
should consider that post-browsing LS length
represents the sum of each year's growth minus
the cunuilati\e reduction by browsing. In
addition to the direct effect of remo\ ing twig
material, browsing might also affect length by
changing the potential for growth. Growth
potential might be affected by the abilit\- of
the whole plant to grow or b\' the number or
t\ pe of buds available, either for tlie w hole
plant or for individual twigs.

Total bud densit\ per plant, expressed as
the sum of the number of flowers, leaf clus-
ters, and LS per unit length of stem, was simi-
lar for browsed and unbrowsed sites (P >
0.10; Fig. 1). However, total bud density did
differ at the twig lexel (P < 0.01) between
browsed and unbrowsed twigs (F'ig. 1). Browsed
plants had a lower (lower bud density iP <
0.001) and higher LS bud densit>- (P < 0.01)
than unbrowsed plants (I^ig. 1). However, at
the twig level (Fig. 1), flower or LS densities
were similar bet\veen browsed and imbrowsed
twigs pooled for all browsed sites. Unbrowsed
twigs from brow sed plants had lower flower (F
< 0.01) and higher LS (P < 0.001 j bud densi-
ties tlian twigs from unbrowsed plants. This
suggests that browsing affects both browsed
and imbrowsed twigs on brow sed plants, which
is a plant-level response. Further, density of
any of the 3 types of buds did not appear to
depend on actual level of browsing per plant,
as 0% to 100% of terminal twigs were browsed
on sampled branches on plants exposed to
herbivores, with /• = 0.07 (P > 0.22) between
bud density and percentage browsed. This
suggests that any degree of browsing affects
flower and LS production on the whole branch
and probably on the whole plant.

0.16

0.14

0.12
u

C 0.1

n

n

E 0.08

E
"55

"D 0.06
3
ffi

0.04 H

0.02 -

Flowers Leaf
Clusters

LS All Buds

Twigs

n Browsed
■ Unbrowsed

Flowers Leaf LS All Buds

Clusters

Plants

Fig. 1. Average number of buds per mm of branch (density) by type of bud structure (flowers, leaves, long shoots).
Comparisons are bet\veen browsed and unbrowsed twigs on browsed plants in = 8), and between plant averages from
browsed in = 7) and unbrowsed (n = 2) sites. Pairs of bars with similar letters are not different (Mann-Whitney test, P <
0.05).

32

Ghkat Basin Natihalist

[Volume 58

Several researchers have attributed low
growth rates to whole-plant effects on vigor
(Hormay 1943, Garrison 1953) or carbohx-
drate reser\'es (Menke and Trlica 1983) and
have recommended moderate browse levels or
specific seasons of use. Tueller and Tower
(1979) reported a lower growth rate in rested
or lightK used plants than in those that were
heavil) browsed, terming this a stagnation
effect. Bilbrough (1990) found that clipped
bitterbrush was able to mobilize inactive buds
for elongation and hypothesized that this
would eventually alter flower and LS ratios.
Although we could detect differences in bud
densit>' (buds per unit length of stem) between
sites and treatments and could construct bud
frequencies from this information, we could
not determine whether changes in frequency
of flowers, leaf clusters, or LS were due to
variable densities before browsing or to bud
differentiation after browsing.

Leaf cluster bud density was 49% lower on
browsed twigs (F < 0.05) than on unbrowsed
twigs (Fig. 1). This decrease did not appear
between browsed and unbrowsed plants or
between unbrowsed twigs from browsed plants
and twigs from unbrowsed plants, suggesting
that this leaf bud response occurred only on
browsed twigs. Possible mechanisms for this
decline include increased mortality of leaf buds
either by physiological effects or by higher
leaf bud density at the distal (browsed) end of
the twig. Ph\si()l()gical effects could include
physical or chemical damage due to browsing
or a change in resource allocation patterns \\ ith-
in the plant to maintain flower and LS bud
numbers at the expense of leaf bud numbers.

Although browsing levels (Table 2) were
statisticalK' the same for the Burned and
Unburned sites, flower bud density was lower
on the Burned site (Table 3) than on the
Unburned site (P < 0.001). Leaf cluster and
LS densities were similar between the two
sites (P > 0.10), apparently unaffected 9 and
10 growing seasons after the fire. Fraas et al.
(1992) had earlier reported that bitterbrush on
the Burned site was significantly lower in
canopy cover (P > 0.01), flower production (P
> 0.1), and seed production (P > 0.1) than on
the Unburned site. Because these 2 sites were
adjacent and environmentally the same (Table
1), including their management before and
after the burn treatment, it is logical to assume
that flower bud densit)' was lowered b\' the
fire just as were the characteristics reported
b\' Fraas et al. (1992). We could not find addi-
tional burned sites to include in our in\estiga-
tion. Therefore, we are uncertain whether
similar results would be the rule, but our find-
ings indicate that a reduction in flower buds
should be anticipated.

The Diy Cottonwood Cattle e.xclosure site
had lower total bud densities than the un-
browsed Deer e.xclosure site (P < 0.01), where-
as flower bud densities (Table 3) were lower
(P < 0.001) and LS bud densities were higher
(P < 0.001) in 1990, as were most other browsed
to unbrowsed comparisons. Although browse
levels (Table 2) were not signifieantK different
(P < 0.10) between the Dry Cottonwood Cat-
tle exclosure and (>attle -I- Deer sites, in 1990
the Cattle -I- Deer site had twice as man\' LS
buds per unit length of stem (Table 3). Other
bud densities did not differ (P < 0.05) bi'tween

Tmuk '■]. Hud (Icrisih (hiids per 100 iiini stem) lor ilowcrs, IcalCliislcrs, aiul lonii slioots (l,S) on all stiiiK sites in UM)
and IfJfJl . riu' 2 imhrowscd study sites arc at Iclt.

Hud

Dfcr

C;attk-

C;att!r

i'owcr

Willow

HR

lli.uli

type

Yt-ar

Huttc-

c.\cl

vxc\

+ Deer

liurii

L'uhurn

Liiu-

Civi'k

Ciildi

Rye

Mower

l<WO

7..5/''/'

(i9'lv

O.t-'^

().7-l-

0.1''^

2.ylHcl>

l.(r''><-

,3.5"lv

2.2alKA

5.()''>v

i'Wl

2.7<''.

2.5"

().()■'>

().7^'l-

O.l-l-

1.1'"

O.laln

().3^'l"

().4^'l>''

O.l.'l"

Ix-avcs

m)()

1().7'>

7.;3">

8. lain y

7.9-1"

10..3l«^

y.7..1».

S.yalK.

95..1UX

lO.Ol"^

1(),5'"-^

l<)!il

fi.,3..l-

8.9'>

(i.r'l«v

5.(v'l"

4.1"'

B.2alHV.

cS.2'"'>

3.5^"

.S.(il«-

4.5^"

I„S

HWO

1.7''l-

1.1'^

3.2''lv

6.1'-^

.4.«'1^

;3.2'''^

;3.4<'lv

3ll,cv

2.1alH.

3()Ihv

nwi

1.0-

1.0'^

2.4^'l>v

3.5IK..I.

2.;3-i"

2.fial.cv

4.7'l'-v

3.7"'>

331KV

(S.O-'

iHow.ntri
^Siti- i-iilri<

•s with siini

ar Irtlcrs U
ir kMrrs (\

Ixilcf) arc Mol
/) lor year nail

simiilicaiitK
s arc not sii:

(lillcrcMlil.Sl).
lilkaiillv ilillcrci

> > oor.i,

tl\Vilco.x(.iil

•St. r > 0.0.5).

1998]

Bi I n.KHiu sii (iiiow III

33

the 2 sites. Few clifferenees lor any t\pe ol buds
were loiiiid anioiit!; hrowsi'd mihunied sites or
between the 2 nnhrowsed sites (Tahle 3).

( irow th

We nieasnred old-urow th hraneh leni:;th (3-,
2-. and l-\r-oId segments), LS growth (annual
growth), and leaf weights (leaf clusters). Total
branch length of old-growth twigs per plant
(Fig. 2) was considerabb' shorter on the (S
browsed sites than on the unbrowsed Butte
and Deer exclosure sites (P < O.OOl), refleet-
ing tlie influence of browsing in modif>ing
branch length. AccordingK; at the Dry Cotton-
wood location the unbrowsed site had longer
branches than the Cattle e.xclosure site (P <
0.01; with only deer browsing), whereas the
Cattle -I- Deer site had the shortest branches
(P < 0.05). Total branch length per plant (Fig.
2) at the Burned and L nburned Steep Moun-
tain sites did not differ (P < 0.10), which indi-
cates that the combination of growth and
browsing (Table 2) was similar between these
sites for the prexious 3 \ r.

The number and length of LS produced
\aried b\ site and year, with 3 sites having
fewer LS (Fig. 3) and 3 sites ha\'ing longer (P
< 0.05) LS in 1991 than in 1990 (Fig. 4). How-

ex er, because these differences were not always
at the same sites, the correlation between
number and average LS length was not signif-
icant (;• = -.12, P > 0.60). As discussed ear-
lier (Fig. 1), LS bud density was highest on
browsed plants (P < 0.01). ilowever, LS bud
numbers (Fig. 3) generally did not differ (P <
0.10) between browsed and unbrowsed plants
largeK' because of longer branches on un-
browsed plants (Fig. 2).

Total I^S length (annual growth; iMg. 5) was
not significantb correlated to total branch
length (r = 0.45, P > 0.13) across all sites.
Although the unbrowsed Butte and Deer ex-
closure sites that had the longest branches
also had high total LS growth, this total length
was not significantly (P < 0.10) longer than on
most browsed sites (Fig. 5).

Long shoot length per unit length of branch
\aried between several sites and sometimes
between years (Fig. 6). This growth rate gen-
erally increased on the MHWMA sites (Power-
line, Willow Creek, Railroad Culch, and High
R\e) in 1991, although all other sites decreased.
Neither total LS length (Fig. 5) nor LS length
per unit of branch (Fig. 6) differed between
the Burned and Unburned sites, although the
Unbunied site had significanth (P < 0.01) more

3000

Butte Deer Cattle Cattle & Bum Unburn Pwrllne Willow RR High Rye

Excl Excl Deer Creek Gulch

Fig. 2. Average total branch length (mm) of 1-, 2-, and 3-yr-olcl hvig segments for plants (n = 10) at all study sites. The
2 imbrowsed sites are at left. Site-to-site, within-year differences (LSD, P < 0.05) are denoted by columns with unlike
letters (abed = 1990. \\:ii\ z = 1991). The asterik (*) denotes a site that had a vear-to-vear difference (Wilcoxon test, P <
0.05).

34

Great Basin Natur.\list

[Volume 58

Butte Deer
Excl

Cattle Cattle & Burn Unburn Pwrline Willow RR High Rye

Excl Deer Creek Gulch

Fig. 3. Average number of long shoots (LS) per branch for plants (u = 10) at all study sites. The 2 unbrowsed sites are
at left. Site-to-site, within-year differences (LSD, P < 0.05) are denoted by columns with unlike letters (ab = 1990, xyz
= 1991). Only those sites denoted by an asterik (*) showed a year-to-year, within-site difference (Wilco.xon test, P <
0.05).

^ 60

E
E.

£ 50
O)

c

0)

-J 40

w

_l
a>

0> 30
flj

(U

>

01990 ■1991

c y
d

Butte Deer Cattle Cattle & Burn Unburn Pwrline Willow RR High Rye

Excl Excl Deer Creek Gulch

Fig. 4. .Average (ii = lOj long shoot ll,S; Icnglli dotal long shoot kiigth di\itlril 1)\ nmni)cr ol long shoots) [K-v biancli
for all study sites. The 2 imbrowsed sites are at lelt. Site-to-site, within-year differences (LSI), P < 0.05) are denoted In
eolminis with nnlikc letters (abed = 1990, wx\/ = 1991). Only those sites denoted In an asterik (*) showed a year-to-
year, \s itliiii-silc (lill( icnee (Wilco.xon lest, P < 0.05).

1998]

BriTKHBRi'Sii Grow III

35

Butte Deer
Excl

Cattle Cattle & Burn Unburn Pwrline Willow RR High Rye
Excl Deer Creek Gulch

Fig. 5. Total lonsi shoot lengtli 'nun) per hraiich (n - 10) for 1990 and 1991 for all stiicK sites. The 2 unbrowsed sites
are at left. Site-to-site, \vithin->ear differences (LSD, P < 0.05) are denoted b\ coliinnis with nnlike letters (ah = 1990,
.\\z = 1991 i. OiiK those sites denoted by an asterik (*) showed a year-to-year, within-site difference (Wilcoxon test, P <
0'.0.5).

Butte Deer Cattle Cattle & Burn Unburn Pwrline Willow RR High Rye

Excl Excl Deer

Creek Gulch

Fig. 6. Long shoot (LS) length per lengtli of branch (mm/mm) (n = 10) in 1990 and 1991 for all stud\' sites. The 2
iiiilirowsed sites are at left. Site-to-site, \vithin-\'ear differences (LSD, P < 0.05) are denoted by columns with unlike let-
ters (abc = 1990, N-wxNZ = 1991). Onl\' those sites denoted b\ an asterik (*) showed a year-to-\ear, within-site difference
(W'ilcmon test, P < 0.05).

36

Ghkat Basin Naturalist

[\ bill me 58

bitterbrush (Fraas et al 1992). The fact that
both the growth rate and the browsing level
(Table 2) were the same at the 2 sites suggests
that browsers remcn ed apjiroximateK the same
amount of LS material from each branch at
each site.

At the Dry Cottonwood exclosine site, LS
length per unit of branch (Fig. 6) was greater
on the Cattle + Deer site than the Cattle
exclosure site in 1990, as was the Cattle exclo-
sure greater than the totalK unbrowsed Deer
e.xclosure that year (P < 0.01). This tendency
supports Tueller and Tower's (1979) stagnation
dieoiy, which predicts relatively higher growth
rates at higher browsing levels. Reiner and
Unless (1982) also reported that livestock graz-
ing increased bitterbrush grow th by reducing
herbaceous competition during the growing
season.

Overall we found only relativeb' minor vari-
ations in the characteristics measured among
browsed unburned sites or between the 2 un-
browsed sites. However, our data indicate a
fimdamental difference in bud allocation pat-
terns between browsed and unbrowsed bitter-
brush plants and suggest that plants protected
from browsing for many years should not be
used as a standard for comparison with plants
exposed to normal browsing pressures. Our re-
sults should increase knowledge of how bitter-
brush responds to browsing. An understand-
ing of the relationships between bitterbrush
growth characters and management strategies
should improve management for bitterbrush
stands and the I)ig-game winter ranges they
often occupy.

Ac;kx()\\li:ix;ments

We thank Dr. Richard F. Lund of the Depart-
ment of .Mathematical Sciences, Montana State
University, for assistance in conducting the
statistical analyses.

LlTERATlIU-: CiTKD

Al.DKliiKH, J.M. 1977. A taxoiioiiiic sliicK ol l)ilUTl)riisli
' I'urshui tridcntdia |Piiisli| D(;.) in Oivj^oii. Uiipiil)-
lislicd iiiiislcr s tlicsis, Orcijoii State I'liivcrsitw Cm-
vallis.

BlI.HHOlc.ll, C.J, 1990. (iroulh responses ol' sanclmisli
and l)itt(Tl)nisli to sirnnlatcd winter lirowsin.H. I'npnli-
lislied master s tliesis, Utali Stale Universit\', Louan.

Ci \Hk. H.C;., CM. Bkiiton, .\\I) KA. Snkva. 1982. Mor-
tality of l)itterl)rnsli alter hurnin^ and cli|)pinu in
eastern Oregon. |ouinal ol HanKf ManaKenient
35:711-714.

Flius, \\'.\\'., C;.L. W.wiBOLi, .\M) M.K. Khi.sn.x. 1992. Pre-
scribed fire effects on a hitterl^rusli-niountain liig
sagebrush-hliiebnnch wheatgrass connnunih'. Pages
212-216 in W.P Clan, E.D. McArtInn; D. Bedunah,
and C.L. Wambolt, compilers. Proceedings of the
symposium on ecologx and management of riparian
shrub communities. USDA Forest Senice, General
Teclmical Report lNT-289, Ogden, UT

Flu.NKLlN, J.F, .WD C.T. DVRNF.ss. 1973. .Natural vegeta-
tion of Oregon and Washington. USDA Forest Service,
Pacific Northwest Forest and Range E.xperiment
Station General Teclmical Report PNW-8, Portland.
OR.

Garrison, G.A. 1953. Effects of clipping on some range
shrubs. Journal of Range Management 6:309-317.

C;ii NTA, B.C., R. Stevens, K.R. Jor(;ensen, and A.R
Pllmmer. 1978. Antelope l)itterbrush: an important
\\ ildland shnib. Utah Di\ ision of Wildlife Research
Publication 78-12.

Glenther, G.E. 1989. Ecological relationships of bitter-
brush communities on the Mount Haggin Wildlife
Management Area. Unpublished master's thesis,
Montana State Universib.; Bozeman.

IIoRMAY, A.L. 1943. Bitteriirush in California. USDA For-
est Service, California Forest and Range Experiment
Station Research Note 34, Berkele\, C.\.

Klkeld, R.C. 1973. Foods eaten b\ the Rock>- Mountain
elk. Journal of Range Management 26:106-113.

Kufeld, R.C, O.C Waliaio, and C Feddema. 1973.
Foods of the Rock->' Mountain mule deer. USDA For-
est Service, Rocky Mountain Forest and Range
Experiment Station Research Paper RM-lIl. Ft.
Collins, CO.

L.w. D.W. 1965. Effects of periodic clipping on \ield of
some common browse species. Journal of Range Man-
agement 18:181-184.

Lund, R. 1991. MSUST.\T statistical analysis package,
microcomputer version 5.00. Montana State Univer-
sit>', Bozeman.

Martinsen, CF. 1960. The effects of summer utilization
of bitterbrush in northccntral Washington. Unpub-
lished masters thesis, Uni\ersit> of Idaho, Moscow.

Menke, J.W., AND M.J. Tri.ICA. 1983. Effects of single and
sequential defoliations on the carbolnchate resenes
of four range species. Jo\nnal of Range Management
36:70-74.

MuE(;(:i,ER, W, and W.L. Siewakt. 1980. (irasslaml and
shrnbland habitat t\pes of western Montana. USDA
Fori'st Sci\ ice, Intermountain Forest and Range
E.xiK'rinicnt Station, (iiMU'ral Technical Hiport INT-
66, Ogden, VT.

N().\A. 1991. Ciimatological data, Montana. 84-94 (1-13).
National Clim;itic Data Center, .\sheville, NC

NoRD, E.G. 1959. Bitterbrush ecology — some recent find-
ings. USD,\ I'orest Service, Pacific Soutliv\est Forest
:in(I Range E.vperiment Station Research Note 148,
Bcrkelcv, CA.

Ri.lNER, R.J., AND PJ. I u\i ss. 1982. Effect of grazing
horses managed .is niani|inlators ol big game winter
range. Journal ol Range Management 3.5:.567-571.

Siiivi'ilERD, M.R. 1971. Effects of ciii^jiing on kev' brow.se
species in southwestern Colorado. Colorado (Jami-,
I •ish. and Parks Division, (;FP-R-l-28, DenviT.

Snidiioii, CW.. \\ii W.G. Cochran. 1989. Sl.ilislic.il
iiiclliods. Iowa Stale University Press. .\mi's,

S()k\i, K.K., WD l':j. Roiiii. 19S1. Hioinrtn. W.ll. I'Vee-
Mian and Co., New York.

1998]

BiTTEHBKLSIl GUOWTll

37

SriiiNHOFK H.W. 1959. Sonu' cfiects of clippintj iMftei-
brush at differfiit intensities. Pages 23-24 in 'IVans-
actions of the lonrtli annual suniiner conference of
the Central Monntains and Plains Section of the
Wildlife Societ\.

TltLLtK. RJ., AND J.D. Towr.K. 1979. W.uetation stagnatioTi
in 3-phase i)itj-ganK' e.xclosnres. JonrTial of i^ange
Management 32:258-263.

iRNESS, PJ., .wn C.H. JiiNSi'N. 1983. Goat use in fall
increases bitterbnish browse and reduces sagebrush
density: Pages 186-194 in A.R. Tiedeniann, and K.I^.
Johnson, compilers. Proceedings of the research and
management of bitterbrusii and chflrose in western
North .•\merica. I Si).\ Forest Sen ice. General Tech-
nical Report I NT- 152.

\\ WIBOLT, C.L. 1996. .Mule dei'r and elk foraging i)refer-
ence for 4 sagebrush tiLxa. Journal of Uangi' Manage-
ment 49:499-503.

WwiBoiT, C.L., W.VV. Fr.us, .\\n M.R. Frisiw. 1996.
Variation in Iiitterbrush iPiirshia triclentaUi Pursh)
crude protein in southwestern Montana. C;reat Basin
Naturalist 56:205-210.

\\iN\v.\RD, A.M., .\Ni:) J. A. FiNDl.KV. 1983. TiLxonomic vari-
ations of bitterbnish {Purshia Iridentata) in Oregon.
Pages 2.5-31 in A.H. Tiedeniann, and K.L Johnson,
compilers. Proceedings of the research and manage-
ment of bitterbrush and clifJrose in western .North
America. USDA Forest Service, General Technical
Report I NT- 152.

YoLTiE, B.A.. B. GHiiirni, am:) J.M. Pickk. 1988. Succes-
sional patterns in bitterbrush iiabitat tvpes in north-
central \\'ashington. Journal of Range Management
41:122-126.

Received 25 November 1996
Accepted 20 May 1997

Great Basin Naturalist 5S(1), © 1998, pp. 38-44

IDENTIT\^ OF MERTENSIA OBLONGIFOLIA (NUTT.)

G. DON (BOIUGINACEAE) AND ITS ALLIES IN

WESTERN NORTH AMERICA

Ahmed M. Waria'

Abstract. — The eurrent status of Merteivsia obhmgifoUa (Nutt.) G. Don and its alhed ta.xa is surveyed. On the hases
of continuously coherent moi-pliological characters and/or regionally correlated \'ariati()ns, more than 30 taxa, including
species, subspecies, varieties, and 1 forma, previously considered different from M. ohlonnifolia, are now placed under
synonymy of this species. Those tiixa currentK' known as A/, fusifonnis Greene, A/. Ixikcri (Jreene, and A/, bakeri \ar
ostcrhoiitii Williams are among the new s\nonyms. Typitication, taxonomy, and morphological prolilems of A/, ohloii^ifo-
lia are discussed.

Key words: Mertensia oblongifolia, typijication, taxonomy, morphology, allied taxa.

Nuttall (1834) described and depicted Piil-
monaria oblongifolia from a collection of plants
made by N.B. Wyeth in 1834 chiefly in the
valleys of the Rocky Monntains, toward the
sources of the Columbia Ki\ er (corresponding
to present-day states of Idaho and Wyoming).

As the Linnaean species of Puhnonaria
(1753) in North America were placed within
Mertensia (Roth 1797), P. oblongifolia Nutt.
was transferred by Don (1838) into Mertensia.
Except for a few additions, Don maintained
Nuttall's description of P. oblongifolia for his
species and was followed by de Caiidolle
(1846), Gray (1875), and Coulter (1885).

M. oblongifolia was later treated as Cerin-
thodes oblongifoliwn (Nutt.) Kuntze (1891).
Kuntze's coiitcmporar\ botanists, such as Nel-
son (1899, 1900), Rydberg (1899, 1900), and
Piper (1906), and subsequent workers on the
genus Mertensia (Macbride 1916, Johnston
1932, Williams 1937, Higgins 1993) have rec-
ognized M. oblongifolia (Nutt.) G. Don as the
correct name. In fact, Cerinthodes oblongifol-
iwn has remained inadequately known since
Kuntze's time and seems never to have been
mentioned again in the literature under Mer-
tensia species in North America.

De Candolle (1846:91) pointed out that M.
oblongifolia was one of the least known species
of the genus Mertensia, but added no luither
discussion. However, de C>andolle's report that
the leaves were more or less pubescent beneath

represents an important additional morplu)log-
ical feature in the taxon.

Macbride (1916) also argued that M. oblon-
gifolia had been misinteipreted. He examined
fragments of a specimen in the Gray Herbar-
ium (GH) which were labeled, in Dr Gra\ s
hand, "M. oblongifolia Nutt.! ex sp. Wyeth!
misit Durand 1861. " He noted that pedicels of
these fragments were veiy sparseK hispid; cah'x
divided nearly to the base, the lobes 5 nun
long, linear-lanceolate; corolla-tube glabrous
within, 10 mm long, limb 5 nun long; filaments
as broad and as long as the anthers; st\le
slightK exceeds. He concluded that the mor-
phological characters of the fragments and
Nuttall's description agreed perfectK-. Williams
(1937:124) also reported the ab()\e-meutioned
fragments in his monograph: "a tiagnu'ut
marked in Dr. Gray s hand ... is probabK
from the type specimen, Wyeth (G)." The word
probably indicates doubt as to the identitx of
the fragment, and actualK Williams doubt
leads to lectotypificatiou of the fragment.

However, the ke\ problems in this stud\
concern the t>'pificatiou, taxonomy, and mor-
phology of the species, (juestions that I ha\e
examined in connection with a proposed rt^ i-
siou of tlie genus Mertensia in North .Anu'rica
(Waila in preparation).

Pidnionaria oblongijolia was (K'scribcd by
Nuttall (1834:43) as follows: ■Clabriuseula, cauli-
simplici erecto, Ibliis lanceolato-oblongis

' Vloiilf 1,. Bran l.ifc Science Museiiiii. Bl(^;ll;llll Viuiim rnivcrsilv. I'ruvii, I r .Sl(>()2, l'S.\ (piesenl address); .W8 N.ull. licduood Ku.id #:M. S.ill l.ik.- Citx
UT M Ufi, USA (permanent address).

38

1998]

Identity ov Mertessia obloxcuullx

39

ohtusiusculis, superioribiis aciitis. Ilorihiis tiihu-
loso-canipanulatis paniculatis i)f(lic(llatis. caK -
(.•il)us al)l)i"e\iati.s, laciniis lin(.'aril)iis aiiitis tili-
atis. Nuttall s (Inscription implies that he had
seen a collection or a specimen with simple,
erect, and subglabrons stem, etc. In his loot-
note Nnttall reported: "Stem ... six to eiiiht
inches: lowei" lea\es commencing some dis-
tance aho\ f the base of the stem . . . and all
more or less puliescent aboxe: panicle tonned
of axillai") approximating clnstei's of (lowers . . . :
coiolla bright bine; style somewhat exserted.
Nnttall thns cxplicitK' stated that he stndied a
collection or at least a specimen with a com-
plete habit "six to eight inches." His carefnl
examination of the position ol the lower lea\es
abo\c the base of the stem and other
described featnres further confirms his posses-
sion of an entire specimen. Don (183(S:372) also
mentioned a plant of 1/2 to 3/4 feet. Unlike
both Nnttall and Don, Gray (1875:53), Mac-
bride (1916:17), and Williams (1937:123) appear
to ha\e seen onK' the fragments of Nuttall's
specimen at the Gra>- Herbarinm (GH).

I have seen Nuttalls plant collection at
British Museum (BM) and the fragmentar>
specimen preserved at GH, the same scraps
seen by Gray (1875), Macbride (1916), and
\\illiams (1937). The fragmentan- specimen is
\ en poor, consisting mostK' of dissected flow-
ers and a single small leaf As correctK' pointed
out b\- Macbride (1916), diis fiagmentaiy mater-
ial is in accordance with Nuttall's description
and the t\pe specimen.

On the same sheet of the t\pe specimen at
13M are 2 other n()n-t\pe specimens. Although
these 2 latter specimens were collected much
later and originate from different localities,
the\' agree with M. oblongifolia. However, as
duplicates of the t\ pe collection may possibly
exist at the Herbarium of Kew Gardens (K)
and/or elsewhere, I choose to designate the
specimen deposited at BM as a lectot\pe and
the fragmentary' specimen preserx^ed at GH as
an isolectot\pe.

The s\nonym\' of M. ohloiigijolid has a long,
complicated histoiy Mertensia longiflora
Greene (1898:261) was based on a collection
made b\' Sandberg and Leiberg in 1893, tenta-
ti\el\ identified and distributed as M. ohlon^i-
folia. It was placed in sxnonym)- oiM. ublongi-
folia by Piper (1906:479), who was followed
b\' Macbride (1916:18). This synonymy was

apparcMitly rejected b>' Rydberg (1922:732),
who kept M. lungiflora a separate species.
H\dberg's position was later supported by
Jepson (1925:842), Williams (1937:136). Davis
(1952:592), and John (1956:.348j. Bodi Williams
and lohii not onK recognized M. longiflora as
a species, but also recognized a number of
s\non\nis under this species. However, the
status of M longiflora has remained at the spe-
cific level since then.

M. foliosci Nelson (1899:243), erected from
a collection made l)\ Kxanston and again ten-
tatixcK identihed and distributed as M. ohlongi-
folid. was also placed in synonymy of M. ob-
longifolia In Macbride (1916:18-19). Macbride
placed M. nutcDis Howell, M. necadensis A.
Nels., M. pubescem Piper, and M. nutans subsp.
subcaha Piper together widi M. foliosa in syn-
on>nn oi M. oblongifolia, making 3 new com-
binations: M. foliosa var. subcalva (Howell)
Macbr, M. foliosa var. nevadensis (A. Nels.)
Macbr, and M. foliosa var. pubescens (Piper)
Macbr. Except for a few modifications, Mac-
bride's synonyms under M. oblongijolia were
later supported by Williams (1937:123, 125,
130). Contraiy to Macbride, Rydberg (1922:
732-733) treated M. foliosa and M. nutans as
different species from M. oblongifolia. Simi-
larly, Tidestrom (1925:467) considered M.
nevadensis, M. foliosa, and M. nutans subsp.
subcaha entities of their own and recognized
Pulmonaha oblongifolia as the onh' sxnonxm
under M. oblongijolia.

Besides Macbrides obsenation on the rela-
tionship between M. oblongifolia and M. foli-
osa. Nelson (1909) studied the affinities be-
tween M. fusifonnis Greene and M. congesta
Greene on the one hand, and M. bakeri Greene,
M. laterifolia Cireene, and M. anioena A. Nels.
on the other. Based on these affinities. Nelson
established 3 new combinations: M. papillosa
fusifonnis (Greene ) A. Nels., M. bakeri anwena
(A. Nels.) A. Nels., and M. bakeri laterifolia
(Greene) A. Nels. Nelson then placed M. papil-
losa fusifonnis under M. papillosa Greene,
while M. bakeri anioena and M. bakeri laterifo-
lia were both placed under M. bakeri. He also
placed M. congesta under M. papillosa, and M.
canescens Rydb. under M. bakeri. Nelson s com-
binations and synon\-m\' arrangements were
apparently rejected b\' both Rydberg (1922:
734, 1932) and Tidestrom (1925:467), who
treated M. bakeri. M. fusifonnis, M. amoena.

40

Great Basin Natl iulist

[Volume 58

and M. hitcrifolia as species. While Rxxlberg
placed M. congesta under A/, fusifunnis, M.
secimdorum Cockerell under M. laterifolia,
and made nomenclatural transfer of M.
canescens into M. cana Rydb., Tidestrom placed
M. paniculata \ar. nivalis S. Wats, under M.
bakeri. As did both Rydberg and Tidestrom,
Williams (1937:100, 118) considered M. bakeri
and M. fiisifonnis separate species each with a
number of s\nonynis. Contrar>' to Rydberg,
Williams placed M. secimdorum under M.
lanceolata (Pursh) A. DC. and M. laterifolia
under M. bakeri.

Johnston (1932:84-85), aware of the strict
ecological relationship between M. foliosa and
its environments, studied this relationship
carefully and affirmed that in response to the
environment, this species exhibited 3 phases
of morphological variation that correspond to
(1) M. foliosa, (2) M. foliosa var. subcalva, and
(3) M. foliosa var. amoena (A. Nels.) Johnston,
respectively. Furthermore, he provided a more
complete set of synonyms under each of these
taxa and suggested that M. foliosa var. sub-
calva was better named M. foliosa var. sub-
calva f macbridei, and M. cusickii Piper and
M. eplicata Macbride as M. foliosa var. amoena
f cusickii (Piper) Johnston. M. obi ongi folia was
not mentioned in Johnston s paper.

In his monumental work, A Monograph
of the Genus Mcriensia in North America,
Williams (1937) published the following new
combinations under M. oblongifolia: M. oblon-
gifolia var. nevadensis (A. Nels.) Williams, and
M. oblo)igifolia var. amoena (A. Nels.) Williams.
He recognized 26 synonyms under M. oblon-
gifolia and its varieties (Williams 1937:123,
125, 130), as did Davis (1952:592). Higgins
(1993:88) later found Williams' varieties of M.
oblongifolia ick^ntieal to the species and placed
these infraspecific taxa into synonynn.

Despite the extensive literature available
on the genus Mericiisia in North America, the
identity of M. oblongijolia and its relationship
with M. bakeri, M. fusiformls, etc., have received
little attention. Lack of information exchange
and/or discordant opinions among earl\ con-
tributors may ha\c' oxershadowcd the signili-
cance ol this rela(i()iislii|) among the taxa in
(|uesti()n.

Ilie purpose ol this paper is to rc\ic\\ all
literature available on the above-mentioned
taxa and examine all t\ pe specimens ol all taxa

in this study. As a result of this review. 1 pres-
ently treat the species M. oblongifolia, M. bak-
eri, M. fusifonnis, M. foliosa, and M. amoena, as
well as most of their current sxnonyms, as a
single moiphologicalK' variable l)ut allied group
(see Tivxonomie Remarks and \'ariations). There-
fore, M. oblongifolia is the only species recog-
nized in this study, while M. fusifonnis, M.
bakeri, and M. bakeri var. osterhoutii Williams
are among its new synonyms.

Although I have not yet examined the M.
longiflora type specimen (Sandberg & Leiberg
s. n.) at the herbarium of Notre Dame (ND),
its cuiTent synonvnis, such as M. pulchella Piper
(1906), M. pulchella subsp. glauca Piper (1906),
M. homeri Piper (1906), M. longiflora var. Jwrn-
eri Macbride (1916), and M. longiflora \ar. pul-
chella Macbride (1916), have been examined
and found to be closely allied to M. oblongifo-
lia. However, as I have not consulted the type
material of M. longiflora, these taxa are not
included in this stud\'. Both M. longiflora and
its synonyms will be placed either in sxn-
onymy to M. oblongifolia or as infraspecific
taxa to it.

M. praecox Smiley, cnrrentK placed under
M. oblongifolia, is now considered different
from this species but rather close to M. arizon-
ica Greene. Also, M. stenoloba Greene (1901)
and M. syniphi/toides Greene (1901), both cnr-
rentK' synon\'ms to M. oblongifolia. were not
treated in this stud\' because 1 was unable to
examine the t\'pe specimens of these taxa,
which are probablv at tlu' herbarium of ND as
indicated by Williams (1937:126, 130) and/or
elsewhere. Ho\\'e\er, M. praecox, M. stenoloba.
and M. syinphytoides will be treated together
with the remaining taxa of the genus Mcrtcn-
sia in North America.

Materials axp Mitiiods

rhis paper is basi'd on a stud\ ol herbariuni
t\ pe material obtained on loan from RM, BR\,
CAS, F, Gil, ORE, RM, US, and WILLU
herbaria (abbreviations according to Holm-
gren et al. 1990), as well as all literature' avail-
able on the subject. In addition, I consulted a
large set of A/, oblongifolia collections, deposited
at BRY and representing the states and coun-
ties in \\ liieh the species occurs.

()nl\ \\('ll-de\i'lope(l llowcrs, nutlets, and
vegetative parts were used for measurements.
Moral parts (when small) were measured

1998]

Idem ri'i ov Mehtessia oblosgifulia

41

under a Baiisch 6: Lonih stcreomicroscopc
alter softeninti in ethaiiol alcohol; a ruler
scaled in mm was nsed lor measurinil laruer
plant parts.

In this stnd\ I have tieneralK lollowi'd ta\-
onomic concepts commonly used in Uixonomic
re\ isions based niainK' on herbarium material.
I consider morpholo^icalK coherent units to
be species; if considerable intnispecitic \aria-
tion is ex'ident, 1 yeneralK discuss it under
Taxonomic Remarks and Variations. All s\ii-
onxnis are listed in chronoloilical order under
the species.

M. obiongit'olia Niitt.j C;. Don, Cen. Hist. 4:372.
1838: de Candolle. Prodr. 10:92. 1846: S. Watson, U.S.
Geol. E.xpl. 40th Par. (Bot. King's E.xped.) 5:238. 1871;
Gray, Proc. Am. Acad. 10:53. 1875: Coulter, Man. Bot.
Rock> Nft. 262. 1885; R>dberg, Mem. N.Y. Bot. Card.
1:336. 1900: Macbride, Contr. Gray Herb. N. S. No. 48:17.
1916: Tidcstrom, Contr. U.S. Nat. Herb. 25:467. 1925;
\\iiliams, Ann. Mo. Bot. Card. 24:123. 1937: Davis, Fl.
Idaho 592. 1952: Higgins, Utali Fl. 88. 1993. Pulmonaria
obloiv^ifolia Nuttall, Jour Acad. Nat. Sci. Phila. 7:43. 1834;
G. Don, Gen. Hist. 4:372. 1838: dc Candolle, Prodr 10: 2.
1846. Cerinthodes ohlongifolhnn (Nutt.) Kuntze, Rev. Gen.
PI. Pt. 2:436. 1891. Type locality: IdahoAVyoming, North-
ern .\ndes. Towards Sources of Columbia River Wyeth s. n.
(BM! lectot>pe, GH! isolectotype, designated here).

M. fHiiiicuJata (AH.) G. Don van nivalis S. Watson, U.S.
Geol. E.xpl. 40th Par (Bot. King's Exped.) 5:239. 1871,
syn. nov. M. nivalis (A\"ats.) R\(lberg, Mem. N.Y. Bot. Card.
1:336. 1900, s\n. now type locality: Utah, Bear Ri\'er
Canyon, VHI.1869, Watson 844 (GHl holotype).

.\/. hakeri Greene, Pittonia 4:90. 1899, syn. no\'.;
Williams, Ann. Mo. Bot. Card. 24:118. 1937. Type locality:
(Colorado, southern Colorado, smnmit of Mt. Ha\den,
14.\"II.]89S. Baker Earle 6c Tracy 576 (ND holot>pe, not
seen, GHl. RM!, USl isotypes).

M.foliosa A. Nelson, Bull. Torn Bot. Club 26:243. 1899,
syn. nov; \\illiams, .\nn. Mo. Bot. Card. 24:125. 1937. Type
locality: Wyoming, southwest Wyoming, on the sagebmsh
slopes in the foothills, 28.V.1897, Evanston 2951 (RM!
holotxpe, GH! isotype).

M. fusifonnis Greene, Pittonia 4:89. 1899, syn. nov.;
Williams, Ann. Mo. Bot. Card. 24:100. 1937. M. papillusa
fusifonnis (Greene) A. Nelson, Coult. and A. Nelson, Man.
Ry. Mt. Bot. 421. 1909, syn. nov.; Williams, Ann. Mo. Bot.
Card. 24:100. 1937. Type localit\-: Colorado, Bob Creek,
West La Plata Mountains, 28.\T.1898, Baker, Eade &
Tracy 206 (ND holotxpe, not seen, F!, GH!, RM!, US! iso-
txpcs).

M. tuhiflora Rydberg. Bull. Tom Bot. Club 26:.544.
1899, syn. nov.; Williams, Ann. Mo. Bot. Card. 24:125.
1937. Type localit)-: Wyoming, Big Horn Mountains, head-
waters of the Tongue Riven \TI.1898, Tweedy 119 (NY
holotype, not seen, GH!, US! isotxpes).

M. anioena A. Nelson, Bot. Gaz. .30:195. 1900, syn.
no\.: Williams, Ann. Mo. Bot. Card. 24:1.30. 1937. M. hak-
eri amoena (A. Nels.) A. Nelson, Coult. & A. Nelson, Man.
R>. Mt. Bot. 422. 1909, s\n. nov.; \\illiams, .\nn. Mo. Bot.
Card. 24:30. 1937. \l. foliosa \an anwena (A. Nels.) John-

ston, Contr. .Arnold .\rb. .No. 3:85. 1932, syn. no\'.: Williams,
Ann. .Mo. Bot. Card. 24:130. 1937. M. oblon{iifolia \an
anioena (A. Nels.) L.O. Williams, .\nn. .Mo. Bot. (;ard.
24:130. 1937, syn. no\-. T\pe locality: Montana, Madison
County, Monida, Glen Creek, Yellowstone Park,
16.VI.1899, Nelson & Nelson 5413, (R.M! holotvpe, BRY!,
GH!, US! isotypes).

M. intermedia Rydbirg. Mnii. N.^'. Bot. (iard. 1:335.
1900, syn. nov; Williams. Ann. Mo. Bot. (iard. 24:125. 1937.
Type local it\-: Montana, Bridger Mountains, 17-18. VI. 1897,
R\(lberg 6c Bessey 4873 (K'\ holotype, not seen, Gil! iso-
t\'pe).

M. congesta Greene, Pi. Baker 3:17. 1901 (article not
seen), syn. nov.; Williams, .\nn. .\lo. Bot. Card. 24:100.
1937. Type locality: Colorado, Poverty Ridge, above
Cimarron, 13.VI.1901, Baker 129 (ND holotype, not seen,
GH!,RM!, US! isotypes).

M. lateriflora Greene, Pi. Baken 3:18. 1901 (article not
seen), syn. nov.; Williams, Ann. Mo. Bot. Gard. 24:118.
1937. M. bakeri lateriflora (Greene) Nelson, Coult. 6c Nels.,
Man. Ry. Mt. Bot. 432. 1909, syn. nov.; Williams 1937:118.
T\pe locality: Colorado, Carson, western Colorado,
21 .VH. 1901, Baker 334 (GH! hololotype, RM!, US! iso-
txpes).

A/, nutans Howell. Fl. N. W Am. 491. 1901 (article not
seen), syn. nov.; Williams, Ann. Mo. Bot. Gard. 24:125.
1937. M. foliosa van subcalva (Piper) Macbride, Contr
Gray Herb. N. S. No. 48:18. 1916. Type locality: Oregon,
on high hills, near Goldcndale, IV 1878 (20. IV 1882), How-
ell s. n. (ORE! holotxpe).

M. coronata A. Nelson, Bull. Torr Bot. Club 29:403.
1902, syn. nov.; Williams, Ann. Mo. Bot. Gard. 24:125. 1937.
Type locality: Wx'oming, Sweetwater Count\', 9. VI. 1900,
Nelson 7071 (RNl! holotype, GH!. ORE! isotype).

M. cusickii Piper Bull. Torn Bot. Club 29:643. 1902,
syn. nov.; Williams, Ann. Mo, Bot. Gard. 24:1.30. 1937. M.
foliosa van anioena f. cusickii (Pipen) Johnston. Contn
Arnold Arb. No. 3:85. 1932, syn. no\.; Williams. Ann. Mo.
Bot. Gard. 24:130. 1937. Type locality: Oregon, Stein's
Mts., eastern Oregon, 18.VI.1901, Cusiek 2582 (article/
specimen) (US! holotype, GH!, ORE!, RM! isotypes).

M. nevadensis .\. Nelson, Proc. Biol. Soc. Wash. 17:96.
1904, syn. nov.; Williams, Ann. Mo. Bot. Gard. 24:125. 1937.
M. foliosa van nevadensis (A. Nels.) (A. Nelson) Macbride,
Contn Gray Herb. N. S. No. 48:19. 1916, syn. nov.;
Williams, Ann. Mo. Bot. Gard. 24:125. 1937. M. oblongifo-
lia van nevadensis (A. Nels.) L.O. Williams, Ann. Mo. Bot.
Gard. 24:125. 1937, syn. nov.; Davis 1952:592; Higgins
1993:88. Type locality: Nevada, Hunter Creek Canyon, 5
miles west of Reno, 16.V1903, Kennedy & True 711 (RM!
holotype).

M. myosotifolia Heller, Colo. Agn Exp. Sta. Bull. (Fl.
Colo.) 100:292. 1906 (article not seen), syn. nov; Williams,
.\nn. Mo. Bot. Gard. 24:118. 1937. M. lanceolata van
nnjosotifolia (Heller) .Macbride, Contn Gray Herb. .N. S.
No 48:15. 1916, syn. nov. T\pe localitx: Colorado, Eagle
Countx; Red Cliff 26. VI. 1900, Osterhout 2164 (MO lecto-
t\pe, selected by Williams, not seen, GH! isolectotype).

M. nutans subsp. subcalva Pipen Contn U.S. Nat.
Herb. (Fl. Wash.) 11:479. 1906; Williams, Ann. Mo. Bot.
Gard. 24:123. 1937. M. foliosa van subcalva (Piper)
Macbride, Contn Gray Herb. N. S. No. 48:18. 1916;
Williams, Ann. Mo. Bot. Gard. 24:123. 1937. M.foliosa
van subcalva f macbridei (.Macbn) Johnston, Contn Arnold
Arb. 3:84. 1932, syn. nov.; Williams, Ann. Mo. Bot. Gard.

42

Gki-:at Basin Naturalist

[Vblume 58

24:123. 1937. Type locality; Washington, Yakima Region,
Rattlesnake Mts., 29.IV.1901, Cotton 328 (US! holotype,
GH!, RMlisotypes).

M. piihescens Piper, Contr. U.S. Nat. Herb. (Fl. Wash.)
11:479. 1906, non de Candolle 1846, syn. nov.; WiUiams,
Ann. Mo. Hot. Card. 24:130. 1937. M. foliosa van piihes-
cens (Piper) Macbride, Contr. Gray Herb. N. S. No. 48:19.
1916; Williams, Ann. Mo. Bot. Card. 24:130. 1937. Type
locality: Washington, Douglas County, Waterville,
23.1\:i900, Whited 1214 (US! holotype, ORE! isot\pe).

M. refracta Nelson, Bot. Gaz. 56:69. 1913, syn. nov.;
Williams, Ann. Mo. Bot. Card. 24:118. 1937. Type locality-
Colorado. Wagon Wheel Gap, 28.\ II. 1912. GrifTin 1.39
(RM! holotype, GH! isotype).

M. eplicata Macbride, Contr. Gra\ Herb. N. S. No.
48:16. 1916, syn. nov. Type locality: Idaho, Boise County,
Dry Buck. 10.V.1911, Macbride 856 (RM! holotype).

M. nehonii Macbride, Contr. Gray Herb. N. S. No.
48:19. 1916; Williams, Ann. Mo. Bot. Card. 24:123. 1937.
Type locality: Nevada, Elko County, Jarbidge, 9.VII.1912,
Nelson & Macbride 1995 (RM! holotype, GH! isotype).

M. bakeri var. suhglabra Macbride ^ Payson, Contr.
Gray Herb. N. S. No. 49:66. 1917; Williams, Ann. Mo. Bot.
Card. 24:123. 1937. Type locality: Idaho, Custer County,
Josephus Lakes, 3.VHI.1916. Macbride & Payson 3544
(GH! holotype, CAS!, RM! isotypes).

M. oblungifolia var. nimbuta Macbride, Contr. Gray
Herb. N. S. No. 53:18. 1918 (article not seen), syn. nov.;
Williams, Ann. Mo. Bot. Card. 24:130. 1937. Type locality:
Montana, Bozeman, 18.V.1893, Gottschalch s. n. (GH!
holotype).

M. cooperae Peck, Torreya 32:151. 1932 (article not
seen), syn. nov; Williams, Ann. Mo. Bot. Card. 24:130.
1937. Type locality: Oregon, Harney Coimty, 6 miles west
of Riley \T.1922, Cooper 11127 (WILLU! holotype, GH!
isotype).

M. bakeri var osterhoutii Williams, Ann. Mo. Bot.
Card. 24:120. 1937, syn. nov. Type locality: Colorado,
Grand County, Sulphur Springs, 8. VI. 1906, Osterhout
.3225 (RM! holotype, GH! isotype).

Perennial 10-50 cm tall, with fairly vvoocK',
thick, .short, erect or vertical rootstocks, u.su-
alK branched at the snmniit; roots numeroii.s
.slender, fibrous, intermingled with few large
woody ones, and the 1-several crown.s closely
covered or clothed with dead brown leaf bases
and dead petioles; stems 1 or more from each
elongated crown, .straight and simple, ascend-
ing to erect, slightly to fairK' conspicuously
striate or angled, smooth or rough, glabrous or
densely pubescent with fine, relatively long,
spreading or closely appressed or crisped-
retrollexed hairs. Leaves alternate, green, thick,
occasionally ample, radical or lower leaves
connnencing some distance above the base of
the stem, few, scattered, petiolate, the upper-
most numerous or crowded at the sinnmit,
sessile to siil)sessile, with lamina linear-Iancc--
olate to lanceolatc-oblong or spatulate to nar-
rowly oblong-ovate, rarely elliptic, 3-12 X

0.5-2.5(4.5) cm, attenuated or tapering, rarely
roimded at the base, acuminate to obtuse,
rarely roimded at the ape.x, entire, scabrous or
sparseh' to densely' ciliate at the margins, gla-
brous to minutely scabrous on both sides, or
sparseK' to densely' pubescent above, glabrous
to scabrous beneath, or densely pubescent on
both sides; midrib prominent; petiole winged,
6-12 cm long, glabrous or pubescent all over.
Inflorescence congested, becoming panicled
with age, with few branches to rather crowded,
formed of a.xillar\' approximating clusters of
flowers; peduncles up to 6 cm long; pedicels
veiy slender and often drooping, 1-10 mm long,
glal)rous or pubescent; caK x dixided nearK' to
the base, 3-8 mm long, enlarging in fruit, gla-
brous or pubescent, lobes 5, 2-5 mm long,
narrowly linear to lanceolate-triangular, acumi-
nate to acute, sparsely to densely ciliate or
hispid at the margins. Plant hermaphrodite;
flowers bright blue, occasionally subtended by
lanceolate foliar bracts; corolla tubular-cam-
panulate, up to 15 mm long, tube 5-12 x 3 mm,
lobes 4-5 mm long, obtuse; stamens attached
at the throat of corolla, free part of filaments
2-4 mm long, usuiilly dilated, crests or append-
ages in the throat between the bases of the fil-
aments conspicuous, with a 10-toothed ring at
the base of the tube; anthers 1.2-2 mm long,
oblong and straight; style 10 mm long, usually
enclosed or somewhat exserted; nutlets 3 mm '
long, alveolar and white .spotted, strongK niuri-
cate, rugose.

Distribution. — Mericns'm uhloHiiijolHi is
widespread throughout the Mountain and
Pacific states of North America.

Habitat. — M. ohlon^iilDha is known in
clumps and moist open slopes. It is also found
on plains, hillsides, and/or mountains with
pine woods. It has an altitudiual range horn
7800 to 13,000 feet (2377-39(i2 m).

Ta.xonomk: remarks and \ aki vhons. —
Mcrtcnsid ()hl(>ii<i,if()Iia is one oi the most mor-
phologicalK \ariable species oi the genus. The
variation is probably correlated yvith geologi-
cal and/or ecological responses. The subcoui-
cal to conical, or shortK hiscicled to cushion-
shaped, or rarely tapering rootstock (caudex)
of most type specimens oi s\nonynis examined
supports such variation. Basal and upper leaves,
often monomorphic in shape, size, and pubes-
ii'uce lor most synonyms of M. ohlon^ijolid. or
rarely dimoiphic in some type specimens such
as M. cusickii (Cusick 2582) and M. eplicata

1998]

Ii)i:n HI"* ok Mliuexsia i)blo\cii()LI.\

43

(Macbride 856), both at HM. fiirtlirr continn
this xariation. Regarding the iiuhiincntiim, M.
()l}I()n<:ifolia xaries from cntircK ulabrous to
coinpleteK pubescent.

\i:k\ ACl l.\H NAMRS. — Bhiebc'll. bluebells,
spindle bliubt'll. wcstt'in bluebell.

ACKNOWI.KnCMF.NTS

This stud\ has been peribnned entireK at
the Herbarium of the Monte L. Bean Life Sci-
ence MustMun of Brigham Young Universit\
(BRY). 1 am deepK gratehil to Dr. Stanley L.
Welsh, C>urator of the Herbarium, for in\alu-
able ad\ice, instructi\e suggestions, and con-
structive criticism of the manuscript. 1 also
thank Dr Duane Atvvood, Assistant Curator,
and staff of the Herbarium for arranging all
loans to BR1'.

I express thanks to Elder Alexander Morri-
son and Dr. Ron Genison, both of the Coipo-
ration of the President, The Chvneh of Jesus
Christ of Latter-da\' Saints, for constant inter-
est and encouragement and for first approach-
ing BYU concerning m\' research activities.
Similar thanks go to the Dean of the College
of Biolog)' and Agriculture, Chairman of the
Department of Botany and Range Science,
and Director of the Life Science Museum, all
of BW. for hosting m\' research and placing
all necessan facilities at m\- disposal.

1 am much obliged to directors and cura-
tors of the herbaria mentioned under Materi-
als and Methods for loan of specimens.

All literature or references needed for the
work ha\ e been obtained through painstaking
work b\' Dr Nathan M. Smith, Science Librar-
ian of the Life Science Museum, as well as the
stair of the Harold B. Lee Librarx of BYU.

Also, many thanks are due my friends and
colleagues at the Monte L. Bean Life Science
Museum for support and encouragement, par-
ticularK, Dr. Douglas Cox, Assistant Director
oi the museum, and Ms. Tern' Simmons, nm-
seum secretary, for introducing me to comput-
ers and related facilities.

Comments and suggestions on the iinal draft
of the manuscript by Dr. Larry C. Higgins of
St. George, Utah, Ms. JoAnne Abel of the
Great Basin Naturalist, and Dr Mats Thulin of
Uppsala Unix ersitx are appreciated.

Financial support has been gixen b\ the
Corporation of the President, The Church of
Jesus Christ of Latter-da\ Saints.

Lrri'RATrHK Ciikd

l)i: CwnoLLK, A.P 184fi. Borraj^ineaf. In: A.P de Can-

ilolle, Prodroimis S>stcMnatis .Naturalis Regni Veg-

ctahilis 10. Paris.
CoCKlilUMA., TD.A. 1907. A lU'w Mi'rlcu.sUi from (lolorado.

Miilileiilx-rgia 3:68.
. 1918. Notes on tlu- flora of Boulder C^oiinty, C^olo-

rado. Torre>a 8(73): 1 77- 1 83.
CoLLTER, J.M. 1885. Manual of the botany of the Hocky

Mountains. I\ison, Blakeman, Taxlor. and C>ompany,

New York and Chicajio.
D\\ IS, R.J. 1952. Flora of Idaho. Brii^hani '\bnni^ Lniver-

sit>' Press, Pro\o. UT.
Don, G. 1838. A general histon.' of the diehlauiNdeous

plants 4. Longman and Co., London.
Cray. .\. 1875. Contributions to the botan\' of .North

.America. Notes on Boraginaceae. Proceedings of the

.American .Acadenn of .Arts and Sciences, New Series

10:48-62.
. 1886. S\'noptical flora of North America 2(1). 2nd

echtion. Ivison, Blakeman, 'ia\lor. and Compan\, New

York.
Greene, E.L. 1898. New or noteuortln species .\.\l. Pit-

tonia 3:257-263.
. 1899. West American Asperifoliae 1\'. Pittonia

4:86-97.
. 1901. Plantae Bakerianae 3. Washington.

IIiGGIXS, L.C. 1993. Boraginaceae. Pages 66-92 in S.L.
Welsh et al., editors, A Utah flora. 2nd edition revised.
Brigham Yoimg University Print Services, Prove, UT

Holmgren, PK.. N.H. Holmgren, and L.C. Barnett.
1990. Inde.x herbariorum, part 1. The herbaria of the
world. 8th edition. Regnum V'egetable 120.

Jepson, WL. 1925. A manual of the flowering plants of
California. Uni\'ersit\- of California Press, Berkeley
and Los Angeles.

John, H.S. 1956. Flora of southeastern Washington and of
adjacent Idaho. Revised edition. Students Book Cor-
poration, Pullman, WA.

Johnston, l.M. 1932. Notes on various borages of the west-
ern United States. Contributions from the Arnold
Arboretum of Hanard University 3:83-98.

Ku.vrZE, O. 1891. Revisio Genennn Plantanmi 2. Leipzig.

Linnaeus, C. 1753. Species Plantamm 1. Edition I.
Holmiae.

Macbride, J.K 1916. The true Mertensias of western
North .America I. Contributions from the Gray Herb-
arium of Hanard Uni\ersit\, New Series 48:1-20.

M.\CBRIDE, J.F!, AND E.B. Pavson. 1917. New or otherwise
interesting plants from Idaho IV Contributions from
the Gray Herbarium of Harvard University, New
Series 49:60-72.

Nelson, A. 1899. New plants from WVoming ATI. Bul-
letin of the Ton-e> Botanical Club 26:236-250.

. 1900. Contributions from the Rock\ Moinitain

Herbarium I. Botanical Gazette .30(3): 189-203.

. 1902. New plants from Wyoming XI\: Bulletin of

tlie ToiTe\' Botanical Club 29:400-406.

. 1904. New plants from Nevada. Proceedings of

the Biological Society of Washington 17:91-98.

. 1909. In: J.M. Coulter and A. Nelson, editors. New

manual of botany of the central Rocky Mountains
(\ ascular plants). Cincinnati and New \brk.

. 1913. Contributions from the Rocky .Mountain

Herbarium XIII. Botanical Gazette .56(1):6.3-71.

44

Gkeat Basin Natur.\li.st

[Volume 58

Nelson, A., and T.D.A. Cockerell. 1903. Three new-
plants from New Mexico. Proceedin,H.s of the Biolog-
ical Society of Washington 16:45-46.

NUTT.\LL, T. 1834. A catalo.mie of a collection ol plants
made chiefly in the valleys of the Rock\ Mountains
or Northern Andes, towards the source of the Colmn-
bia River Boragineae. Journal of the Academv ot
Natural Science of Philadelphia 7:43—45.

OsTERHOLT, G.E. 1917. A new Mertensia. Torreya 17:
175-176.

Piper, C.\' 1902. New and notevvorthv nortliv\estern plants
VU. Bulletin of theToney Botanical Club 29:642-646.

. 1906. Flora of the State of Washington. Boragina-

ceae. Contributions from the United States National
Herbarium 11:472-486.

Roth, A.W 1797. Catalecta Botanica 1. Leipzig.

Rydberg, PA. 1899. New species from the western
United States. Bulletin of the Torrey Botanical Club
26:541-546.

. 1900. Catalogue of the flora of Montana and the

Yellowstone National Park. Boraginaceae. Memoirs
of the New York Botanical Garden 1:326-337.

. 1904. Studic^s Oil the Kockv Mountain Flora XIII.

Bulletin of the Torrev Botanical Club 31:631-655.
. 1922. Flora oi the Rockv Mountains and adjacent

plains. Hafner Publishing (-o.. New York.
. 1932. Flora of the prairies and plants of central

North America. New York Botanical Ciarden, New-
York.

rmisTKoM. I. 1925. Flora of Utah and Nevada. Contribu-
tions from the I'nited States National Herbarium
25:7-635.

W.'VTSON, S., ET.AL. 1S71. Botany. In: C. King, editor United
States geological exploration of the fortieth parallel.
Government Printing Office, Washington, DC.

W'lixiAMS, L.O. 1937. A monograph of the genus Meiien-
sia in North America. Annals of the Missouri Botani-
cal Garden 24:17-159.

Received 7 May 1997
Accepted 11 Aiigmi 1997

{;rcal Basin Nalunilist 58(1). © 199S, pp. 4.5-53

ASTRAGALUS (LEGUMINOSAE): NOMENCLATURAL
PHOI'OSALS AND NEW TAXA

.Stanley L. Welsh'

Abstkaci. — As [lait of an ontioinu sunun.ir\ revision of Astragalus for the Klor.i NOrlli .Vnierica project, several
noTiieiK-latural changes are iiulicated. .Nonienelatural proposals include A. molyhdvnus var. simltzioritm (Barneby)
Welsh, eoml). nov.; A. australis \ar aborigiiumim (Kiehardson) Welsh, comb. no\-.; A. aiistralis var. cottoni (M.E. Jones)
Welsh, comb, nov.; A. australis var lepagei (Ilulten) Welsh, comb, nov; A. australis \ar. muriei (Hiiltcn) Welsh, comb,
nov; A. suhcinereus van sileranus (M.E. Jones) Welsh, comb, nov.; A. tegetarioides var «;i.v/i/.v (Meinke & Ka\c) Welsh,
comb, nov; A. ainpullarinidcs (Welsh) Welsh, comb, nov; A. cutleri (Barneb)) Welsh, comb, nov; and A. laccoliticus
I M.E. Jones) Welsh, comb. n()\. Proposals of new hixa include A,s/r«^'«/t/.S' sect. Scytocarpi subsect. Microcymbi Welsh,
siiliseet. nov. am! .A. sahiilostis \ar. ichictihis Welsh. \ar iio\. .A leetotype is selected for I'liacd (iiistriili.s L.

Kci/ words: .Astrai^alns. lunncnrldturi'. new taxa.

Astragahts, with more tlian 350 species and
a ijreat many infraspecific taxa, is perhaps the
largest genus of North American plants. Its
compkwitx' has long been recognized as evi-
denced In its tangled nonienelatural history.
E.xperts and others interested in tliis \ ast genus
lia\ e encountered enormous problems in deal-
ing with it, especialK' prior to 1964. In that
year Rupert Banieby, in his classic account (in
m\' opinion, the most impressive taxonomic
work of the century), untied the Gordian knot
of nomenclature, typification, and classifica-
tion oi Astragalus for North America. Regard-
less of when a taxonomic \\ ork is attempted,
there will be shortfalls in information avail-
abilitv; in ade(]uac>' of specimens, in confluence
of data from disparate regions, and in overall
iniderstanding through time. Despite those
problems, the Atlas of North American Astra-
galus (Barneb\- 1964) will stand for all time as
a remarkal)le attempt to understand this huge
genus and as a tribute to Bameby's genius.

It is hoped that the proposals discussed here-
in represent some helpful minor additions to
the work by Barnebx; whose treatment is re-
flected in a large manuscript now in prepara-
tion for the Flora North America (FNA) project
by S.L. Welsh and R. Spellenberg. Included
below are sufficient portions of that treatment
to allow the current proposals to be put into
perspective and to be used b\' workers prioi- to

appearance of the entiie manuscript \\ithin the
FNA publication schedule. Format is as under-
stood for the FNA publication; order of treat-
ment is ph>'logenetic as per Barneb); or as per
present modification.

Astragalus mohjhdenus Barneby, Leafl. W. Bot.
6:70. 1950. Leadville milk\etch.

Low, looseK' matted, shortK' caulescent
perennials, 0.5-6 (14) cm long, from extensive-
ly branching subterranean caudex branches.
Pubescence strigidose-pilosulous, basifi.xed.
Stems largeK subterranean, the aerial tips
prostrate or ascending. Stipules 2-5 mm long,
all connate-sheathing. Leaves 1.5-7 cm long;
leaflets (9) 17-25, 2-10 nun long, ovate, ovate-
oblong, or elliptic, obtuse, mostly crowded,
folded or involute. Peduncles 1-3 (6.5) cm
long; racemes loosely 3- to 6-flowered, the axis
scarcely elongating, 3-10 (15) mm long in
fruit; bracts 2.5-5 mm long; pedicels 0.5-2
mm long; bracteoles 0-2. Calyx 5.2-7 nun
long, the tube campanulate, 3-4.2 mm long,
the teeth subulate, 2-3 mm long. Flowers
10.7-12.5 mm long, pink-purple, lilac, or
whitish, the banner veined and suffused with
lilac, recurved through ca 45°, the keel tip
maculate. Pods ascending, sessile or nearly so,
7-11 (12) mm long, 3-3.5 mm thick, obliquely
()\()id or ovoid-ellipsoid, somewhat incuned,
l-loculcd, strigulos(\ Ovules 6.

'Department of Botan> and Range Science. ;uicl M.I,. Bean Life Science Museum. Brighani Young Universit\', Pro\o. UT 84602.

45

46

Great Basin Natl r.\list

[Volume 58

1. Lciillfts ol upper It'axfS 17-25; racemes 3- to (>
flowered; plants of central Colorado and 'leton
Co., Montana \ar. inolyhdciiiis

— Leaflets of upper leaves 9-17; racemes mostl>- 1-
or 2 (exceptionally 3)-flo\vered; plants of the Salt

River Range, Lincoln Co., \\ yoming

\ar. simltzioriiiii

Astragalus mohjbdemis van mohjhdenus

[hasi'd on; A. phuithcii.s IJanieln, Lcall. W. Hot. .5; 195.
1949, non .A. jAiinihcus (JontscharowJ.

Dwarf alpine plants, the caudex deepK sub-
terranean, the branches rhizomatous. Stipules
2-5 mm long. Leaves 1.5-7 mm long, (the
uppermost) with 17-25 leaflets, 2-10 mm long.
Peduncles 1-3 (6.5) cm long, the racemes 3- to
6-flowered. Calyx 5.2-7 mm long, the tube
campanulate, 3^.2 mm long, the teeth subu-
late, 2-3 mm long. Flowers 10.7-12.5 mm
long, pink-pui-ple, lilac, or whitish, the banner
recui-ved through ca 45°. Pods rather abruptly
contracted into a short beak. Ovules 6. *Type:
"Colorado: . . . about 4 miles east of Leadville,
Lake County . . . Ripley & Bameby No. 9994
. . . west slope of Mosquito Pass, east of Lead-
ville, No. 10045"; syn types CAS!; isosyn types
CH!, K, NY!, POM!, RM!, RSA, US, WTU.*

Flowering July, August. Alpine timdra com-
munity at 3780-3965 m, along the Continental
Divide, along the boundaries between Gunni-
son-Pitkin, Lake-Park, and Park-Sunnnit coun-
ties, in central Colorado, and disjunct in Teton
Co., Montana.

Astragalus molyhdenus \ an shultziorum
(Barneby) Welsh comb. nov.

[based on; A. sliiiltzioniiii Barneby, Brittonia 33; 156.

1958).

Dwarf alpine plants, the caudc.x deepK
subterranean, the branches rhizomatous. Stip-
ules 2-3 mm long. Leaves 1.5-7 (8) cm long,
the uppermost with 9-15 (17) leaflets, 2-7 mm
long, lance- or oxate-clliptic, obtuse to acute,
mostl) distant, flat or loosel> folded. Pedun-
cles (0.5) 1^ cm long, the racemes (usualK' 2-)
1- to 3-no\vered. Calyx (5) 5.7-6.7 mm long, the
tube caiii[)aniilate, (3) 3.4—4 nun long, the teclli
subulate, 1.8-3.3 nun long. Flowers 11-12
nun long, whitish laxcnder tinged, the bainicf
veined and suffused with lilac, icc in\ cd
through ca 50°, the keel tip niacnlate. Pods
tapering to an elongate beak. Ovules S of 9.
*Type: "Wyoming. Lincoln (.'onnly; stonx hill-
top, 9500 ft, moimtains near (Cottonwood
Lake, E of Smoot, 31 Jul 1923 (fl), E.B. iVson

iic G.M. Armstrong 3651," holot\pe POM!; iso-
typesMO, NY!,WYO.*

Flowering July, August. Alpine tundra and
kinmniholz or on talus, at 2865-3150 m, in
Salt Ri\er Range, Lincoln Co., Wyoming.

Plants of the 2 varieties are essentialK iden-
tical in aspect, but the features noted in the
ke\- appear to be substantial diagnostic ones.

Astragalus australis (L.) Lam., Fl. Fr 2:637.
1778. Subarctic milkvetch.

\Phaca uustnilis L., Mant. PI. 1:103. 1767].

Moderate, caulescent perennial, (10) 20-30
cm tall, from a superficial caudc.x. Pubescence
silky-strigose, villous, or villous-tomentose,
basifi.Kcd. Stems erect or ascending, few to
several. Stipules (1) 2-7 (11) nun long, often
veined, semicoriaceous, at least the lowermost
connate-sheathing. Leaves (1) 2-7 (10) cm
long; leaflets (5) 7-15, 3-28 (35) mm long, 1-7
(8) mm wide, oblong, linear-elliptic, elliptic, or
linear-oblong, acute, xillous to glabrate on bodi
sides. Peduncles 2-10 (14) cm long; racemes
2- to 40-flowered, rather cc^mpact and ascend-
ing at anthesis, the axis 1-15 cm long in fruit;
bracts 1.2-5 nun long; pedicels 0.8-3.5 nun
long; bracteoles 0. Calyx 3.7-6.4 mm long, the
tube 2.1-5 mm long, campanulate, villous, the
teeth 1-3 mm long, subulate. Flowers 7.5-
14.5 mm long, ochroleucous or suffused with
pink, the wing petals bilobed apicalb, the ban-
ner recurved through 40-50°. Pods pendu-
lous, stipitate, die stipe 2.5-8 (10) nun long,
the body oblicjuely and narrowly elliptic in
outline, 13-27 nun long, 3-9 (11) nnn wide,
semibiloculai; the septum 0-0.6 nun wide,
glabrous or jKibescent. 0>ules 8-16; 2n = 16,
32, 48. *T\pe: "llabitat in alpinis Ilelvetiae,
Italiae, Gallo Provinciae," lectotxpe here des-
ignated, illustration of "Astragaloides Alpina
snpina glabra, foliis anctioribus, in Tilli, ('at.
PI. Ilort. Pi.sani 19.5. 14. f 1. 1723!*

American materials of. A. australis are por-
tions ot a \ast eirinniboreal speeii'S complex
demonstrating gri'al \aiiabilit\. beginning
with the t\pical mateiial in southern Furope
and extending eastwiiid. Asi;itie plants passing
under the nanu-s A. Iii<j,araiu>rii lkisile\ skaja,
.A. <:,()r()(lk(>rii Jurtsi'\, .A. lolmafzitii jnrtse\,
and .A. kohiiiiciisis Jnrtsex (Korobkox et al.
198(i) belong to this com])lex, with the entities
li;i\ing the same degree ol nioipliologieal
intc'grit) (or lack theriM)f) as the .American
mateiials. N'arietal segregation within flie North

1998]

A.STRAC;A/.( S NOMKNCLATURE

American \ariants has been l)asi'(l on dillei-
ences in [Miheseence, leaflet shape, and pod
size and shape. Several varieties Ikim' hccn
proposed, with the best sumniarx that oi
Banieby (1964:137). Often threat variation
occurs within a single popnlation, but some ol
the proposed ta\a ha\e apparent ii;e<)^raphical
correlation; others are haphazard or represent
a mere contimnnn. Man> of the \ariants can
be determined mechanicalK on a 2n basis,
essentialK as sunnnari/.ed by Barnebx. It will
be possible b\ usinti tlu' following ke\' to iden-
tif\ till' most conspicuous morphological, but
admittedK transitional, \ariants. \arial)ilit\ is
the rule within the species, antl a niori' detailed
segregation, though possible, might separate
moqDhologicalK similar indi\ iduals — not taxa.
Perhaps even the following proposals do not
represent ta.\a, per se, but there are hints of
correlation of some features with geogiaphical
and ecological distributions.

1. Flowers 7-5-11 (12) mm long; caKx 3.5-5.9 mm
long; plants of broad distribution.
2. Lea\es petiolate; plants from eastern Al.iska

and Yukon \ ar. initrici

2. Leaves sessile, the lower pair of leaflets aris-
ing from the stipules, appearing as if foliose
stipules; plants from southern Yukon south-
ward (Rock") Mts. and OKmpics).
.3. Pods .3-7 (9) mm broad, seldom much ii at
all bladder}-; peduncles 6.5-15 cm long;

plants widely distributed

\ar. ahoriginorum

3. Pods 7-9 (11) mm broad, bladdery
inflated; peduncles 3-6.5 cm long; plants
known only from the OKmpic Mts., Wash-
ington van cottoni

1. Flowers 11.5-13.8 (14.5) nun long; caly.x 5.7-6.5
mm long; plants from west central to northern
Alaska, east to northern Yukon and .Northwest
Territories \an lepagei

Astra^ahifi australis miv. miiriei (R> dberg)
Welsh, comb. nov.

[based on: A. ahoriginorum \ar nnihei Ilulten, Fl.
.Alaska & Yukon 1080. 1947: Atclophragiiui Uncarc
Rydberg, Bull. Torre\ Bot. Club 40:50. 19131.

Stems 7-35 cm long, ascending. Leaves (2)
3-6.5 cm long; leaflets (7) 9-15, 6-15 mm
long, linear to narrowly elliptical, acute to
obtuse, glabrous to strigulose-pilosulous or
villous. Peduncles 2.5-11 cm long, t\picall\
longer than the leaf Racemes rather denseh
to somewhat loosely (6) 8- to 21 -flowered, the
axis 1.5-9.5 cm long in fruit. Calyx 4.2-5.5
mm long, the tube 2.4—2.7 mm long, campanu-
late, strigulose to villous, the teeth 1.1-2.5 mm
long, narrowK' subulate. Flowers 8.5-9.5 mm

long, whitish to purplish. Pod stipe 4-6 mm
long, the b()d\ oblicjucK ellipsoid to narrowly
oblong, 1 1-24 nun long, 4-7 mm wide, the
valves glabrous to occasionally strigose. *Type:
Alaska, "Central Yukon R. distr: Porcupine R.,
45 miles from its mouth, O.J. Miuic 2162,
June 26, 1926," holotype S!*

Flowering June, JuK'. Mountain slopes, ridge
crests, meadows, and less commonK' on gravel
bars, at ca 2()()-86() m, east central Alaska, and
British and l^arn mountains of northern "^'ukon,
and in the "^'ukon Ri\er Valley and \icinit\ of
Kluane National Park, southwest Yukon.

13iagnostic criteria that would separate speci-
mens from northern '^'ukon, those with petio-
late leaves, from plants at the t\pe localitx of
A. australis, sens, str, in the Alps of southern
Europe, are not resolved herein. They appear
to be essentialK' identical. Petiolate specimens
occur throughout the range of van nuiriei as
here inteipreted. The t>pe of this \ariet\ has
strigulose pods, unusual in plants from the
Arctic, but pubescence does not seem to have
diagnostic xalue within the group. Many of
the uuiriei specimens were from ridge tops,
especially in northern Yukon, with a smaller
number from stream graxels (the apparent
preferred habitat of most of var. lepagei, q.v.).
Plants from southwestern Yukon are more
nearK uniform and belong to the 'linearis'
phase, whose t>'pe is from the famous Lake
Labarge (now^ "Laberge," collected by J.B.
Tarlton in 1899, holotype NY!, isotype US!).

Astragalus australis var. lepagei (Hulten)
Welsh comb. nov.

[based on: A. lc)Hig('i Hulten, l-'l. Alaska 6: Yukon 1761.
1950; A. tugariiuirii Basile\skaja; A. lohnaczcvii Jurt
sev].

Stems (8) 24-40 cm long, sprawling to
ascending. Leaves 3-9 cm long, sessile or def-
initely petiolate; leaflets (5) 9-15, 6-33 mm
long, elliptic to lanceolate, lance-oblong, lin-
ear-lanceolate or linear, acute to apiculate,
glabrous to strigulose, pilosulous, or villous.
Peduncles (4) 4.5-10 cm long, typically longer
than the leaf Racemes rather densely to
loosely 8- to 29 (32)-flowered, the axis 3-14
cm long in fruit. Calyx (4.7) 4.8-6.5 cm long,
the tube 2.8-5 mm long, campanulate to
deeply so, black strigulose to villous, the teeth
(1) 1.4-2.4, narrowly subulate. Flowers (9.5)
11.5-13.8 mm long, whitish to purplish. Pod
stipe (3) 5-7 mm long, the body obliqueK
ellipsoid to narrowly oblong, (10) 15-30 mm
long, (3) 6-8.5 mm wide, the valves typically

48

Great Basin Natliulist

[Volume 58

glabrous. *Type: "Arctic (>oast distr.: Liuiat,
July 29, 1948, Lepage 23601," holohpe S!*

Flowering June, JuK; Often on gravel bars,
but also on spits, beaches, and less commonly
on ridge crests in mixed tundra, from near sea
level to 350 m, from coastal western Alaska,
along the northern and southern slopes of the
Brooks Range, south to near the 65th parallel,
and east to the ranges of northern Yukon and
continental and insular Northwest Territories,
Canada.

Plants from northern Alaska, Yukon, and
Northwest Territories are \'ariable also but
seem to revoKe about a group of plants from
sand bars, spits, and beaches with overall
larger flowers and broader pods. Well-devel-
oped, large-flowered collections from the Cov-
ille Ri\'er at Umiat were sufficiently distinc-
tive that Hulten (1950:1761) compared them
with A. harringtonii (Rydberg) Hulten of the
rohhinsii complex. Even those large-flowered
specimens are part of a continuum, with small-
flowered plants forming the other extreme,
especially in coastal western Alaska. In north-
em Yukon the large -flowered material is tran-
sitional with smaller flowered plants assigned
herein to var. uuiriei.

Astragalus australis var. aboriginorum
(Richardson) Welsh, comb. nov.

[based on autonym of: A. ahori^inlorjitiu \dr.j(tsti<:,i()riiin
M.E. Jones, Rev. Astrag. 135. 1923, i.e., A. ahoh^inontiu
RicharcLson in Franklin, Jour, Append. 746. 1822; Phaca
glahriusciila Hooker, Fl. Bon Amen 1:144. 1831; A.
i^hiliiiiisnihis var major A. Gray, Proc. Acad. Nat. Sci.
I^hiladelpliia 1863:60. 1863; A. misfralis van glahrius-
culm (Hooker) Isely, Syst. Bot. 8:421. 1983; A. for-
icoodii S. Watson; A. richardsonii Sheldon; Atelophrag-
ma widlowense Rydherg; Atelophrag,ina herriotii Ryd-
bcr^\ Astrafialus scnipidicola Female! & W'eatlierhx],

Stems 10-50 cm long, ascending. Leaves
sessile, 1-7 (10) cm long; leaflets 5-15, 3-27
(35) mm long, linear to oblong, lanceolate, or
elliptical, acute to obtuse, glabrous to strigose
or villous. Peduncles 6.5-15 cm long, typicalK
longer than the leaf. Racemes rather denscK
6- to 40-ll()wered, the axis 1.5-15 cm long in
fruit. Flowers 7-12.5 mm long, whitish to pur-
plish. Pod stipe 2.5-8 mm long, the bocK ob-
li(jnely ellipsoid to narrowly oblong, 10-30 mm
long, 3-7 mm wide, the xaKcs glabrous fo
occasionally strigose. Ovules 8-16. *T\])e: tal-
lies of the Rocky Mountains. I)i iiiniiiond,
holotype K.*

Flowering May to July, (iraxcl bais, sIohn
shores, talus, ridge- crests, and meadows, grow-
ing with an innnense array of plant species

through its huge geographical range, at ca
20-3630 ni; Yukon east to Gaspe, and south to
Oregon, Nevada, central and northern Utah,
(>olorado, and western South Dakota.

The var. ahoiiginontin consists of the aggre-
gation of variants distributed in the mountains
and valleys from northern British Columbia
southward, exclusive of the isolated var. cot-
toiii. Separation of the "linearis' phase in the
Yukon from the northernmost outliers of var.
ahoriginorwn is rather tenuous. However, most
of var. muriei (including the linearis phase)
have petiolate leaves, at least at the lower
nodes. And the great bod\ of specimens south
along the cordillera have sessile leaves, but
include a great many variable specimens,
often growing intermixed within the same
populations. Further segregation seems futile
at present.

It is unfortunate that the synonymy, already
overcrowded, should have yet another name.
Insistence on priority of autonyms in recent
codes of botanical nomenclature has led to
such clutter. In this case the earliest auton\-m
available for the geographically most extensive
American variety is "aboriginorum." Bameby
(1964, et subsequent) cited the name as '\ibo-
riginutn but later used the suffix -orun} for
taxa named b>' him.

Astragalus australis var. cottoni (M.E. Jones)
Welsh, comb. nov. Cotton's milkvetch.

[A. cottoni M.E. Jones, Rev. Astrag. 13.5. 1923, nom.
nov. pro: A. oliiiii))ictis Cotton, Bull. Tonex Bot. Cluh
29:573. 1902, non A. olijmf>icits Pallas, 1800; A. aus-
tralis var oh/mpicus (C^otton) Isel\, S\st. Bot. 8:421.
1983, nom. illeg.; Atclophnif^iiia cottoni (M.E. Jones)
R\(ll)ers].

Stems 1-1.7 dm long, decumbent to
ascending. Leaves (1.5) 2-5.5 cm long; leaflets
9-15 (17), 4-16 mm long, linear-elliptic to
elliptic-oblanceolate, acute to subacute, \illo-
sulous or glabrate abo\c'. Peduncles 3-6.5 cm
long, t\pically equaling or somewhat longer
than the leaf Racemes rather denscK' 11- to
21 -flowered, the axis 2-6 em long in fruit.
Flowers 10-12.2 nun long, creann white. Pod
stipe 3-5 nun long, the bod\ semi-ellipsoid,
bladdery iuilated, 20-25 mm long, 7-9 (11)
mm thick, the \al\es glabrous. 0\ules 10-15.
*T\pe: "OKinpic Mts., Ciallaui (louulx, Jul\,
19()(), A.D.E. Elmer"; holotxpe W S; isol\pi'S
NY!, ORE, P US!.*

Elowc'iing June, July. Ridge tops and talus,
on granite at 1380-1680 m in the OKuipic
Mts., C>lallam (^o., Washington.

1998]

Astragalus Nom enclatu re

49

Tliis is the most (listincti\ e of the \ ariants
within tlie austnili.s complex in North Amer-
ica, hence its recognition pre\iously at specific
le\el. It is isohited b\' man\ kilometers from
other tiLxa in the complex.

Astragalus suhcinen'iis A. Cira\. Proe. Amer.
Acad. 13:366. 1878. Siler's milk> etch.

Low, canlescent perennial, 14-90 em long,
racliatiny; from a snhterraneaii. branching
caudex. Pubescence \ illosulous or hirsntnlous,
basifixed. Stems lew to se\eral, prostrate to
weakly ascending, buried for a space of (1)
2-10 (15) cm. Stipules 1..5-6.5 mm long, at
least some connate-sheathing. Leaves 1.5-8.5
cm long; leaflets 9-23, 2-16 mm long, 1-8.5
(10) nun wide, oblong to oblanceolate or obo-
vate, obtuse, emarginate, or retuse, villosulous
on both surfaces or glabrate aliox'e. Peduncles
1.5-10 cm long; racemes 5- to 37-llowered,
the flowers ascending to declined at anthesis,
the axis 1-7 cm long in fruit; bracts 1-3 mm
long; pedicels 0.5-2.5 mm long; bracteoles
0-1. Calyx 3.4-6.3 mm long, the tube 2.3-3.6
nun long, campanulate, villosulous, the teeth
0.9-2.9 nun long, subulate. Flowers 6-11 mm
long, ochroleucous and commonly suffused
with purjile. Pods spreading to declined, sub-
sessile, inflated, ovoid-ellipsoid to ellipsoid,
12-27 nun long, (3.5) 6-13 mm wide (when
pressed), suliterete to dorsoventralK- com-
pressed, think \ill()sulous, mottled. Ovules
10-20.

Much of the material from Kane, Garfield,
and Washington counties, Utah, differs from
the txpical plants in Mohave Co., Arizona, in
being more leafx' (the leaflets 4—10 mm broad),
in ha\ing longer stems (3-7 dm longj, and in
having more firniK' walled pods (15-28 mm
long, and 6-10 [13] mm thick). These Utah
plants belong, sens, str., to van caraicus M.E.
Jones (i.e., the autonym van silcranus).
Although the features are weak and overlap-
ping, they form a syndrome of characteristics
indicative of an e\olutionar\ trend and are
lierein treated at \arietal le\el, bringing to 3
the number of taxa w ithin the species.

1. Mature pods ovoid-ellipsoid, (5) 6-13 mm wide;
flowers .5-9 mm long; stems mostly 14—70 cm
long; plants commonK' of sedimentar>' gra\els,
sometimes from igneous substrates, southern
Utah and northern Arizona.

2. Pods ellipsoid, turgid, but not liladden
inflated, more than twice as long as broad (or
if shorter, then differing othenvise; stems

prostrate, radiating from the root crowni; plants
of Cariield, Kane, Iron, and eastern Washing-
ton counties, Utah, and Ijiicoln Co.. Ne\ada

\ar. silcraiiu.s

2. Pods ovoid or ovoid-ellipsoid, bladden,' inflated,
less than twice as long as broad; steins
ascending or less commonK prostrate; plants
of Coconino and Moliaxe counties, Arizona,

and IJncoln (^o., northern Nevada

van subcinereus

1. Nhilure pods elliptic-()l)l()ng to oblong, 3..5-6 (7)
nun wide; flowers (S..5-11 mm long; stems 40-90
cm long; plants of igneous gravels in eastern

Sevier and western Emer\' coimties, Utah

\ an basalticus

Astragalus suhciucrcus \ an subcinereus

I^lants w ith stems to 5 dm long or k'ss. witli
mature pods relatively broad, maiuK 6-13 nun
wide, and othenvise differing as in the key.
*Type: "Mokiak Pass in the northwestern part
of Arizona, near the Utah Ijoundary, Dn E.
Palmer, 1877," holotvpe GH!; isotypes K, MO,
\Y!, PH, US!*

Ponderosa pine, pin\'on-jiuiipen and sage-
brush communities at 1670-2410 m, in
Garfield, Iron, Kane, and Wasliington coun-
ties, Utah; Lincoln Co., Nevada; and Mohave
and Coconino coimties, Arizona.

Astragalus subcinereus van sileranus (ALE.
Jones) Welsh, comb. nov. Siler's milkvetch.

[based on the auton\ in of A. sileranus \ an curiacus

M.E. Jones, Proc. CaUf Acad. Sci. 11. .5:642. 1895; A.

sileranus M.E. Jones, Zoe 2:242. 1891; Phaca silerana

(M.E. Jones) Rydberg].

Plants prostrate, radiating from a root
crown, with stems to 6 dm long, often conspic-
uousK' flexuous. Pods ellipsoid, mostly more
than twice longer than broad (or if shorter, less
than 7 mm wide and the texture leatherx).
*Type: "Collected b\ me [M.E. Jones] on June
23, 1890, in Sink \alle\, southern Utah, at
about 7000 feet altitude," holot\pe POM I, iso-
txpes CAS!, GH!, MO, NY!, US!*

Flowering May, June. Ponderosa pine,
aspen, oak, piuNon-jimipen and mixed moim-
tain brush communities at 1700-2750 m, in
Garfield, western Kane, eastern Washington,
and Iron counties, Utah; and Lincoln Co.,
Ne\'ada.

Astragalus subcinereus van basalticus Welsh,
Great Basin Naturalist 38:302. 1978. Basalt
milkvetch.

Plants with stems to 8 dm long, with mature
pods narrow, mainb 3.5-6 (7) mm wdde, and
otherwise differing as in die key. *Type: "Utah,

50

Great Basin Natuiulist

[V<:

58

Sevier Co., 16 km S ot Fremont Junction, S.L.
Welsh, D. Isely, & G. Moore 6447, 23 JuK
1967," liolot>'pe BRY!, isotype ISC!*

Flowering Ma\, June. Pinyon-juniper and
ponderosa pine communities at 1380-2430 m
in western Emery and eastern Se\ier coun-
ties, Utah.

Specimens of \an J)(i.s(ilticits grow sxinpatri-
calh' with A. jlexuusiis var diehlii (M.E. Jones)
Bameby. When material of the latter variet\' is
robust, it approaches var. basalticiis in habit,
but not in pod and flower size. Indicated, how-
ever, is a close alignment bet\veen the 2 taxa,
and var. basalticiis might possibly be treated
within an expanded A. flexuosus var. diehlii or
within A. siihcinereiis. The more robust nature
of var. basalticiis precludes alignment with A.
flexuosus, however.

Astragalus sect. Scytocarpi subsect.
Microcymbi Welsh, subsect. nov.

IhuM'cl on; A. inicrDCiiiithii.s Banieh\. Anier. Midi. Nat-
uralist 41:499. 1949.1

Perennial, caulescent, with a shortly sub-
terranean caudex. Pubescence basifixed. Stip-
ules dimorphic, at least the lowermost con-
nate-sheathing. Leaves with 9-15 oblong-obo-
\'ate oi- obovate-cuneate, emarginate, folded
leaflets. Racemes loosely (3) 7- to 14-flowered.
Calyx 2.2-2.6 mm long, the tube 1.4-1.9 mm
long, the teeth 0.5-0.7 mm long. Flowers
5.6-5.8 cm long. Pods 6-9 mm long, obscureK
stipitate, almost or quite bilocular. Ovules 4-6.

The subsection is monotypic.

Astragalus microcymbus Barneby, Amer. Midi.
Nat. 4 1 :499. 1949. Skiff milkvetch.

Slender, diffiise, caulescent perennial, 25-60
cm tall, from a shallowly buried caudex.
Pubescence strigulose to subvillosulous, basi-
fixed. Stems prostrate or weakly ascending,
subterranean for a space of 1-3 cm. Stipules
1..5-3 mm long, at least the lower ones connate.
Leaves (1.5) 2-4 cm long, shortly petioled or
the uppermost subsessile; leaflets 9-15, ob-
long-ovate or ()i)l()iig-cuneate, 3-9 nnn long,
emarginate. Peduncles (0.8) 1.5-3.5 cm long,
variously hairy; racemes looscK (3) 7- to 14-
flowered, the axis (1) 2-6.5 cm long in fruit.
Flowers 5.6-5.8 mm long, whitish tinged with
lilac, the banner recur\c'd through ca 45°.
Calyx 2.2-2.6 nnn long, the tube 1.4-1.9 nmi
long, campanulatc or obcouic-c ainpaiiiilalc,
strigulose with whiti- and fuscous hairs, the
teeth 0.5-0.7 mm long, subulate. Pods pendu-

lous, obscureK stipitate, the stipe ca 0.4 nun
long, concealed by the calyx, the body ellip-
soid or lance-ellipsoid, 6-9 mm long, (2.5j
3-3.3 mm thick, obcompressed, the valves
white-\'illosul()us, almost or (juite 2-loculed,
the septum 0.8-1.3 mm wide. Ovules 4-6.
*Type: "Colorado: . . . four miles west of Gun-
nison, Gunnison Co., ... 20 JuK 1945, fl. & fl.,
Riplev & Barneby No. 7179 ; holotxpe C>ASl;
isotypes COLO, GH!, RSA.*

Flowering July, August. Dr>, sand\ and
gravelK' sites in sagebrush, at 2310-2640 m, in
hills west and southwest of (Umnison, Col-
orado.

Despite conjecture that the skiff milkxftcli
might represent a recent introduction from
unknown source, its ecological placement is
not unlike that of numerous other species of
Astragalus. There is no reason to believe that
it is other than indigenous and endemic. It has
been relocated numerous times since its initial
discoven'. Previous placement within section
Strigulosi is, however, open to (juestion. More
apparently it belongs within the Sc>tocarpi,
near A. gracilis.

Astragalus tegetarioides M.E. Jones, (>ontr
W. Bot. 10:66. 1902. Bastard kentrophyta.

Prostrate, caulescent perennial, forming mats
or cushions 1-3 (4) dm wide, radiating from a
branching caudex. Pubescence strigose or thin-
K \'illosulous, basifixed. Stems 5-15 cm long
or more. Stipules 0.8-3 (5) nmi long, at least
the lower ones connate-sheathing. Leaves 1-4
(6) cm long; leaflets (5) 7-11, 1.5-5.5 (7) nnn
long, obo\atc>-cuneate, obtuse, truncate, or
emarginate, pubescent on both sides. Pedun-
cles 0.3-2.5 cm long; racemes compactK or
loosely (2) 3- to 6 (8)-fl()wered, the flowers
ultimately declined at anthesis, the axis 3-15
nnn long in liiiit; bracts 1.2-2.7 nun long;
pedicels 0.4-1.3 nnn long; bracteoles 0. Calyx
(2.2) 2.6-3.7 nnn long, the tube 1.1-2 nnn
long, obconic-campanulate, the teeth 1-1.9
mm long, subulate. Flowers 4.4-6 (7) nun
long, whitish, the banner laintK lilac-\ lined.
Pods spreading, sessile, the bod\ 3.5-4.5 nun
long, 1.5-4.2 nun wide, oxoid-lenticular, ob-
scurely trigonous, minnli'l\ slrigulost- to silkx
\illous. Ovules 2-;> (4).

1. Kai'cliu's lociscK 1- Id (i I Sl-llnw crcil; tlowers
wliilisli, the liaiiucr willi pale lil.ic miiis. 4.4-7
mm loiii;; pods 1.5-2.S mm wide; plants oi ilanu-x'
Co., Oifgoii \ar. tegetarioides

1998J

AsiHM.MA s Nomenclature

51

1. Racemes compactK- (7) 9- to IS-flowered; flowers
rose purple, tlie banner with a pale basal eye,
6.5-10 (12) nun long; pods 3.2—1.2 nun \\ iclc; plants
of Lassen Co., California \.ii. <iti\iiis

Astragalus tc^ctarioides \ ar, tefictarioidcs

Pubescence strigose-.stri^iilose. Leaflets
7-11, 1.5-5.5 mm long. Racemes 1.3-1.8 cm
louii. loosely 2- to (i (8)-n()\\(Mc-(l. Calyx (2.2)
2.(i-3.7 mm loni;;, tlu- ti'clh 1-1.9 mm long.
FloNNcrs 4.4-(i (7) nmi long, the banner re-
lieved 7()-l()0°. Pods 3.3-4.5 nnn long, 1.5-2.8
inm wide. '^'Type: "Xo. 2619 Cusiek, southern
Blue Mts., Oregon, in sancK soil in the Buck
Range, lune 28, 1901": holotvpe POM!; iso-
tvpes G, (;il', K. MO. XD. XY!, ORE, R RM,
LS!*

Dr\ pine forests and sagebrush communi-
ties at ea 1350-1550 m in the Little Juniper
Mountain and upper SiKies River, in west
central and north Harney Co., Oregon.

Astragalus tegetarioides van anxius (Meinke
& Kaye) Welsh, comb. nov.

|.A. aitxiii.s Meinke (k Kaye, Madrono 39; 194. 19921.

Pubescence loosely villous to pilosulous.
Leaflets 9-15, 4-9 mm long. Racemes 0.8-2.2
em long, compactly 7- to 13 (15)-flo\vered.
Calyx 3.2-4.7 (5) nnn long, the teeth 1.7-2.7
nun long. Flowers 6.5-10 (12) mm long, the
banner reflexed 60-80°. Pods 3.5^.5 mm long,
3.2—4.2 mm wide. *Type: "California, Lassen
Co., Ash \'alle\, ea 25 km west of Madeline
and U.S. Hwy. 395, immediately south of Ash
\'alle\ Rd., in loose gravel overlying volcanic
bedrock, on the boundarv of T38N, RUE,
Sect. 32 and T37X, RUE, Sect. 5, ca 1550 m,
16 Jul 1991, Meinke and Lantz 6108," holo-
t\pe OSC; isotvpes CAS, ISC, MO, NY, RM,
UC. US.*

.\rid flats in or near juniper-sagebrush
steppe or Pinus jejfreiji woods at 1540-1660
m, in Ash \'alle\', extreme north central Lassen
Co., California.

Astragalus ampullar ioides (Welsh) Welsh
comb. nov. Shivwits milkvetch.

[A. crcmiticu-s \ar. ampullariuidca Welsh. Cireat Basin

Naturalist 46:262. 1986].

Moderate, caulescent perennial, 20-63 cm
tall, from a branching subterranean caudex.
Pubescence thinly strigulose, basifi.xed. Stems
decumbent to erect, buried for a space of 2-10
cm. Stipules 3-9 mm long, all distinct. Leaves
5-22 cm long; leaflets 13-21, 4—24 mm long.

3-17 nun wide, o\ate to obovate, lanceolate,
or elliptic obtuse to retuse, strigose (along
veins) beneath, ciliate, glabrous above. Pedun-
cles (4) 9-23 em long; racemes (15) 20- to 40-
flowered, the flowers ascending anthesis, the
axis (4) 10-16 cm long in fruit; bracts 1.5-4
mm long; pedicels 0.7-3.5 nmi long; bracte-
oles 0-2. Calyx 5-6 nnn long, the tube 4-5
mm long, short-ex lindrie, strigose, the teeth
0.5-0.9 (1.2) nun long, triangular to subulate.
Flowers (11) 14-18 mm long, ochroleucous,
the keel immaculate, the banner recurved
through ca 25°. Pods erect, slenderly stipitate,
the stipe 7-15 mm long, the body oxoid to
ellipsoid, inflated, papery, 12-18 mm long,
8-10 (12) mm thick, obcompressed, glabrous,
essentially unilocular, the septum to ca 0.2
mm wide. *Type: "Washington Co., Utah . . .
ca 1 mi N hwy 91 at Shivwits, 3450 ft. elev
S.L. Welsh, N.D. Atwood 21049, 21 April
1982,"holotypeBRY!*

Flowering April, May. Gypsiferous sub-
strates, in "boils on the Chinle Formation sur-
roimded by creosote bush, other warm desert
shrubs, and juniper communities at ca 1050-
1150 m from the Petrified Forest section of
Zion National Park, west in several disjunct
populations to the type locality, Washington
Co., Utah.

The Shivwits milkvetch was dismissed as
ta.xonomically inconsec^uential by Barneb\
(1989) and by Isely (1996). However, the com-
bination of subterranean caudices, fistulose
stems, ven' large number of flowers on an
attenuated raceme, and paper)' inflated pods
seems to be a rather consequential grouping
of taxonomic features, especially in a plant
with a preference for harsh ecological sub-
strates. Diagnostic criteria are of the order of
magnitude of those utilized elsewhere to dis-
tinguish the closely related A. ensifonnis M.E.
Jones from A. rninthorniae (Rydberg) Jepson.
The nature of the root crown and of the pods,
but not of the remainder of the plant, is remi-
niscent of the only slighth- allopatric A.
ampullahus S. \\4its()n. Plants of the Shivwits
milkvetch are routinely hedged back by deer.
Often the entire inflorescence is consumed.

Astragalus cutleri (Barneby) Welsh, comb,
nov. Cutler s milkvetch.

[A. preussii \ an cutleri Bameb\-, Great Basin Naturalist
46:2.56. 1986].

Moderate, caulescent, short-lived peren-
nial, often flowering as an annual, 10-30 (35)

52

Great Basin Nati kalis r

[\blunie 58

cm tall, from a superficial caudex. Pubescence
sparingly strigulose to subglabrous, basifixed.
Stems few to several, ascending to erect,
forming bush\' clumps. Stipules 2-6.5 mm
long, all distinct. Leaves 3-13 cm long; leaflets
5-17 (19), 3-17 (20) mm long, (3) 5-12 mm
broad, elliptic to lanceolate, oblanceolate or
oboxate, acute to obtuse or mucronulate,
strigulose to glabrous below, glabrous above.
Peduncles 2.5-10 cm long; bracts 1.5-2.5 mm
long; racemes 5- to 9-flowered; pedicels
1.5-2.5 mm long; bracteoles 2. Calyx (7.3)
7.5-8.5 (9) mm long, the tube 5.9-6.7 long,
cylindric, pale purple or whitish, sparsely black-
strigose, the teeth 1.3-1.7 (2.3) mm long, sub-
ulate. Flowers 15-16 nun long, white or tinged
(or drying) purplish, the banner recurved
through ca 40-45°. Pods ascending to erect,
stipitate, the stipe 3-3.5 mm long, the inflated
bod> oblong-ellipsoid, 14-18 mm long, 9-11
mm thick, the valves thinly cartilaginous,
greenish suffused (sometimes) with purple,
unilocular, glabrous. Ovules 20-38. *Type:
'"Cutler 2283, Copper Canyon, 1 mi from
mouth, San Juan Co., Utah," holotype NY!,
isotypesCAS!,WIS.=^

Flowering April, May. Saltl)ush and black-
brush communities, on Permian formations, at
ca 1155-1250 m, at Copper Canxon south of
San Juan Arm of Lake Powell, San Juan Co.,
Utah.

This taxon, when first characterized, was
known only from plants flowering as annuals.
Later collections demonstrate that the plant is
at least a short-lived perennial. The other
characters hold, however, even if there is more
overlap in leaflet number than previously
known. Also, the pods are of thin texture,
approaching A. eastwoodiae more so than A.
})reussii, with which it shares features of
ascending-erect pods. Cutler's milkvctch dif-
fers from A. preussii in about the same order
of magnitude as does A. cast wood iae.

Astr(i<i(dus .s(dnd()sus M.F. Jones, Zoe 2: 239.
1891. Cisco milkvctch.

Kobust, ill-scented, caulescent pcic luiial,
13-38 cm tall, from a woody superflcial caudex.
Pubescence strigulose, basili.xi'd. Stems decuni-
beut lo asceudiug or erect, several to iiuiiu'ious,
foruiing clumps. Stipules 4-9 mm loug, all
distinct. Leaves 3-10.5 cm long; leaflets 5-1 1,
6-35 (50) nun long, 3-17 unu wide, rhombic-
oval to obovatc or elliptic, nuicronate, strigose

to glabrous on both sides. Peduncles 3.5-7 cm
long; racemes 4- to 10-flowered, the flowers
ascending-spreading at anthesis, the axis 0.5-2
cm long in Iruit; bracts 2-6 nmi long; pedicels
2-5 mm long; bracteoles 0-2. Calyx 15-17.5
mm long, the tube 11.5-14 nun long, cylin-
dric, strigulose, the teeth 3-4 mm long, subu-
late. Flowers (23) 27-34 nun long, ochroleu-
cous, fading yellowish or white fading off-
white. Pods spreading to declined, subsessile,
inflated, cylindroid, 20-48 mm long, 10-15
mm thick, stiffly paper>' to leatheiy strigose,
unilocular. Ovules 55-59; 2n = 26.

1. Flovver.s 27-34 mm long, ochroleucoiis, fading
\ ellowisli; plants of the Cisco-Thompson \ icinit\

\ ar. sahiilosiis

1. Flowers 23-27 nnn long, white, fading off-white:

plants from northwest of Moab

\ar. vchiculu-s

Astragalus sahidosus var. sabidosus

[Joiwsiclla sahulosa (M.E. Jones) R\ dherg].

Calyx 15-17.5 mm long, the tube 11.5-14
nun long, cylindric, strigulose, the teeth 3-4
mm long, subulate. Flowers 27-34 mm long,
ochroleucous, fading yellowish. Pods spread-
ing to declined, subsessile, inflated, cylin-
droid, 20-48 mm long, 10-15 mm fliick, leath-
eiy. *Type: "Collected [by M.E. Jones] May 2,
1890, at Cisco, Utah, on gravelK soil near
Grand River"; holot\pe POM!*

Flowering late March to Max. Mat-atriple.\-
shadscale conununities at 1300-1600 m on
Mancos Shale (and Morrison Foruiatiou';^) in
the Cirand River Valley, vicinity of Thouipson
and Cisco, (irand Co., Utah.

The \ery large, pale ochroleucous flowt-rs
are borne in late March through April and b\
mid- May the plants bear large sausagelike
fruits. The Cisco milk-vetch is a primaiy sele-
uiuui indicator with close affinities to both \ar.
rcliiciiliis and A. iscli/i Welsh (q.v.), from bofli
oi which it can be distinguished b>- its ochro-
leucous flowers that fade \ellow (\Velsh 1994).
1'he flowers of A. sdhulo.siis \ar sahnlosii.s are
the largest within A.s7/Y/i,7///rs in Utah, and pos-
sibK' elsewhere (though llie\ luv uol the
lougesl). Undeistaiuling ol dixcrsih williin
the Sdhulo.siis complex was long held in abi'X -
aiicc because of paucitx of flowering speci-
mens in lieibari;i. Those llial were collected
wc'ic taken in fruiting condition, i'loial lea-
tures icadiK allow segregation oi the known
po|)ulations into 3 taxa, A. i.sclij, A. sdhiilosus
\ ar. Sdhiilosus, and A. sahulosus var. vehiciiliis.

1998]

A.s77Uc;.ALr.s Nomknclailhl:

53

Astragalus sabulosus \ an vchiculus Welsh,
^ ar. n()\.

Siniilis \;ir. sahtilosi scd in lloiihiis iiiiiioi-
ihiis (2-27 ncc 27-34 nun) ct alhidis (nee
oehroleueis) deeolore albidis (nee flavis) et
leguniinil)us snhstipitatis ineipientibus. *Type:
Utali. (irand Co., T24S, R20E, Sec 7, ca 16 mi
clue XW of Moab, ca 4500 ft. elev. Morrison
Formation, mixed salt desert slnub eoinm., 28
Apr 1984, S.L. Welsli 22709, liolotxpe BHV!, 3
is()t\pes distribnted pre\ iousK as Astra<i,alits
sahitlosus* Additional specimens (all BUY!):
L tall, (rrand Co., ca 1 km SSE of historic state
station and 20 km \\V of Moab. at ca 1404 m
ele\., 30 April 1984, S.L. Welsh & D. Trotter
22723 (fl.); do, 20 May 1985, S.L. Welsh 23432
(fr.); do, 21 Ma\' 1984, At\\ood, Goodrich, and
Thompson 9700; do, T24S. R20E, SI6 SESW
ca 1.8 miles \ of Conrthouse Hock, 16 June
1995, D. Atwood 20276.

Calyx 12-16 mm long, the tube 11-13 mm
long, c>lindric, black strigulose, the teeth 2-3.5
mm long, subulate. Flowers 23-27 mm long,
w hite, fading whitish. Pods spreading to de-
clined, subsessile to incipiently substipitate,
inflated, c\lindroid, 28-45 mm long, 9-13 mm
thick, stiff!) leatheiy,

Shadscale, woody-aster, galleta commimit\
on the Morrison Formation at 1370-1465 m
near the head of Courthouse Wash, Crand
Co., Utah.

Plants of \ar cehicuhis. the stage station
milk\ etch, approach A. isehji in flower color
but ha\e much larger flowers. They are geo-
graphicalK disjimct, b\' more than 35 km from
A. isclyi and about that distance from the
nearest known population of var. sabulosus.
The sabulosus complex is also allied with A.
praelongus Sheldon, which has much smaller
flowers and pods.

Astragahis laccoliticus (M.E. Jones) Welsh,
comb. no\. Laccolite milkvetch.

[A. cicaddc \;ir. laccoliticus M.E. Jones, Proc. Calif.

Acad. Sci. 11. ,5:672. 1895].

Perennial, acaulescent, 4—8 cm tall, fiom a
taproot and superficial caudex. Pubescence
dolabrifonn. Stems obsolete or essentialK* so,
the internodes obscured by stipules. Stipules
2-5 mm long, all distinct. Leaves 2-9 cm long;
leaflets (5) 9-11, (4.5) 5-11 mm long, 3.5-6.5
mm wide, oblanceolate to obo\ate, obtuse,
strigose on both sides. Peduncles 1.3-6 cm
long; racemes 3- to 8-flowered, the flowers

spreading-ascending, the axis 3-15 cm long in
fruit; bracts 2-5 nun long; pedicels 1-2.5 mm
long. Calyx 10-11.5 mm long, the tube 8.5-10
nun long, cxlindric, strignlose, the teeth 1-2
mm long. Flowers 19-27 nun long, pink-pur-
ple, fading or drying ochroleucous. Pods
ascending (humistrate), sessile, the body
15-25 (27) mm long, 7-15 mm thick (when
pressed), turgidK lance-oxoid, contracted dis-
tally into an incur\ed, laterally compressed
beak 5-8 mm long, fleshy, the valves ca 2 mm
thick, shrinking in ripening, green or purplish,
but not mottled, strignlose, unilocular. Ovules
ca 38. =^=Type: M.E. Jones. "No. 56581. July 21,
1894, at (Jottrells Hanch, Henry Mountains,
Utah, 6000° alt.," holotype POM!*

Salt desert shrub, Bigelow sagebrush, and
juniper comnumities, at 1460-1890 m, in
western Wayne and western Garfield counties
(HeniT Mts. and vicinity), Utah.

The laccolite milkvetch is easih' distin-
guished from A. chanmeh'ucc A. Gray b>' its
lance-ovoid (not ellipsoid, purple-mottled
pods). The ta.xon has been confused with the
nearby A. consobrinus (Barneby) Welsh, with
which it shares structurally similar but much
larger pods and flowers, and has been treated
previousK as a variety of A. cJiaiiuwIcuce,
whose distribution is adjacent to but not con-
fluent with that of this plant. Its moiphological
differences are similar to those regarded as
diagnostic in other ta.xa within the Argoplnlli.

Literature Cited

BARNliBV, R.C. 1964. Atlas of North .\iiu'rican Astr(i<i.aliis.
Memoirs of tlie New ^'ork Botanical Carden 1.3:
1-1188.

. 1989. Faliales. Pages 1-279 in A. Cronquist et al.,

Intemioiintain flora 3B. New York Botanical Garden,
Bronx, NY.

HULTEN, E. 1950. Flora of Alaska and Ynkon. X. Dicotyle-
doneae. Lunds Lniv. .Vrssk. N.E A\d. 2. 46(1):
148.5-1992.

ISELY, D. 1996. Native and naturalized Leuuniinosae
(Fabaceae) of the United States. Unpublished manu-
script. Iowa State University, Ames. 1000+ pp.

KOKOBKOV, A.A., M.V. SOKOLLOVA, N.N. T.\1USK1NA. AM)

B.A. JURTSEV. 1986. Leguminosae. Flora .Arctica
URSS 9(2):1-187.
Welsh, S.L. 1994. Leguminosae. In: S.L. Welsh et al., A
Utah flora. 2nd edition. Brigham Young University,
Provo, UT

Received 1 7 April 1997
Accepted 29 May 1997

Great Basin Naturalist 58(1), © 1998, pp. 54-65

REGIONAL ASSESSMENT OF WADABLE STREAMS IN IDAHO, USA

CliristopluM r. Hohinson'- atid G. \\'a\iK' Nlinsliall'

Abstract. — There has been a resurgence in appKing l^ioassessnient techniques for e\aluating and monitoring the
biological integrit\' of stream ecosystems. In till cases biological metrics have been refined to account for regional variation
in aejuatic habitats and faima. This study evaluated environmental and macroinvertebrate properties for wadable streams
in 3 major ecoregions of Idaho: Northern Basin and Range, Snake River Plain, and Northern Rock\' .Mountain. These 3
ecoregions constitute >8()9^ of the land area in Idaho. Reference streams were delineated from test streams in each
ecoregion using standard haliitat assessment protocols (Plafkin et al. 1989). Multiple discriminant anaKsis effectively
detennined habitat (ciuantified measures) and macroin\ertebrate differences between reference and test streams within
ecoregions, although the results suggested that (juantifiable habitat measures (e.g., water chemistiy and nutrients) and
biotic metrics based on ta.\onomic groups (e.g., % Elmidae) improved the discriminatory power of evaluation procedures.
Our results support die contention of a multi-metric approach for assessing differences among streams within an ecoregion.
Lasdy, individual metrics differed in their importance for evaluating stream condition among ecoregions, fi^irther empha-
sizing die importaTice of regionally stratifying metric selection or scoring procedures.

Key words: hioassessment, ecoregion. Iiabitat. Idaho, macroiincrtehrates, pJiospJiorua.

Although tlie Clean Water Aet directs the
U.S. Environmental Protection Agency to
develop programs to evaluate, restore, and
maintain the integrity of its waters, freshwater
lakes and streams continue to be seriously
degraded by nonpoint source pollutants and
habitat alterations associated with various
land-use practices (Benke 1990, Hughes et al.
1990, Karr 1991, Hughes and Noss 1992, Allan
and Flecker 1993, Richards et al. 1993, 1996).
Historically, water quality assessment focused
primarily on chemical criteria and single-factor
kiboratoiy to.xicity tests. The nature of non-
point source pollution (e.g., sedimentation) and
related changes in ph\'sical habitat, however,
requires alternative methods for assessing the
biotic "health" of freshwater systems (Minshall
1996). Presentlx; many states have implemented
an ecoregion approach in their bioassessment
programs (e.g., Fausch et al. 1984, Gallant et al.
1989, Southerland and Stribling 1995, Barboui-
et al. 1996). An ecoregion (areas of similar geog-
raphy, Indrology, climate, chemistry, terrestrial
vegetation, and biota) approach was adopted to
account for geographical differences (variabil-
ity) in freshwater habitats and fauna, and the
differential resj^jouse of respective regions to
aiilIir()|)og( iiic impacts (Bailey 1989, Gallant

et al. 1989, Hughes et al. 1990, Matthews et al.
1992).

Rapid bioassessment protocols ha\'e become
an important tool in the biological e\ aluation
of stream ecosystems (KaiT et al. 1986, Plafkin
et al. 1989, Karr 1991). These protocols are
based on a strong theoretical framework in
community and ecos>stem ecolog\', although
specific metrics usualh' are modified to adjust
nationally derixed or general criteria to meet
regional conditions (Steedman 1988, Barbour
et al. 1992, Resh and McElravy 1993, Barbour
et al. 1996). Rapid bioassessment protocols were
developed originalK' for the time- and cost-
effective collection of biological data, although
compromising data completeness (e.g., (jualita-
tive sampling technicjues) and reliabilit\ (e.g.,
no measiue of data \ariabilit\ resulting in a
loss of statistical power and potential tor lype II
errors; Resh and Jackson 1993). More specifi-
cally, rapid bioassessment attempts to use
regional biota to determine water and habitat
quality, and thus exaluate stream ecos\stem
integrity and hciilth (Rosenberg and Resh 1993,
Barbour et id. 1996). For example, protocols ha\e
been dexcloped using lish, nuieroinxcrtebrates,
and algae to prox ide a wunv integiatixc i-c()S\s-
fciii-Ic'\ el assessment ol biolo^ieal iiilegritx

'Stream Ecology CfiitiM. nc|)ailiiiiiil d Hi<)li)«ical SLiiiict-s, Idaho Sl.it.- riii\<isil>. I'lK-ati'lKi. II) S:i2(m.

^Present address: Departiiicnt orLiiiiiioloKy. Swiss Kederal Institute orKininiiirTicnI..! Sii.iuv and r<ilni(il(m\ (IvWACi. l.licrl.nidstrassc I.W, CII-SlitK)
DueheridoH, Switzerland. Address all correspondence and reprint re(|nests to lliis aiiMidi

54

1998]

Bu)a.s.si:.ssmi:m ov Idaho Sikeams

55

(Biainl)K-tt and Faiiscli 1991, Barhoui- ct al.
1992. Hi'icc and Wolilenherti 1993j. Idaho
recentK issued a niniiIxT of nionitoring proto-
cols thai list- tish (Chandk-r and Nhirct 1993) or
niacroinxi'rtt'hratfs (Cdark and Marct 1993) in
conjunction with habitat e\aluation guidelines
(Burton 1991. Burton et al. 1991) for assessing;
the biological integrit) of it.s streani.s.

The present stucK' incorporated rapid bio-
assessnient protocols for assessing the biologi-
cal conditions olwddable streams in the North-
ern Basin and Kange (NBR), Snakc> River Plain
(SRP), and Xordiern Rocky Mountain (NRM)
ecoregions within Idaho. We examined a \aii-
et\' of habitat and biotic measures used lor
assessing the biological integrit\' of lotic sys-
tems and exalnated dieir respectixe applicabil-
it\ to conditions found in these 3 ecoregions.
We focused our work on the NBR and SRP
ecoregions in the southein part of the state in
1990 and 1991. and included the NRM eco-
region in 1993 (Robinson and Minshall 1995a).
These 3 ecoregions constitute >80% of the
land area in Idaho. We examined the respon-
si\eness of measures among streams that dif-
fered in the degree of impact b\' land uses
characteristic of the particidar region. Undis-
turbed or "least" impacted streams, which sei"ve
as the reference condition for determining
degree of degradation of test streams, thus pro-
\ ide the foundation for developing predictive
models (generalizations) regarding sti-eam integ-
iit\ in a particular area or ecoregion in Idaho.

M ETHODS

Selection of Study Sites

Wie selected study sites from candidate
streams b\' re\'iewing existing literature con-
cerning site conditions, by discussing options
with \ari()us agenc> personnel (Bureau of Land
Management, Idaho Di\ision of Enxironmen-
tal Quality, Idaho Department of Fish and
Game, and United States Forest Sei^vice) and
pri\'ate landowners, and by field reconnais-
sance. Where possible, we made special effort
to select designated "stream segments of con-
cern" (Clark 1990, Dunn 1990). Site locations
range from the IdahoA\Voming border to the
Idaho/Oregon border; man\ sites are accessi-
ble onl\- \ ia a dirt track or by foot. Eight> -fixe
2nd- to 4th-order streams (after Strahler 1957)
w ere selected for analysis and included refer-
ence (r) and test (t) sites in each ecoregion

(NBR: r = 14, t = IS; SPR: r = 16, t = 12;
NRM: r = 16, t = 9). Test sites in the NBR and
SRP ecoregions are usually lowland areas per-
turbed priniariK by lixcstock grazing and other
nonpoinl source agricultural inputs. Mining is
the major land use in the NRM. A complete
list of stud)' streams and specific locations can
be found in Robinson and Minshall (1995a).

C'ollection Piocc 'dines loi' Phxsical
and Chemical Measures

InitialK, we evaluated habitats using (juali-
tatixe habitat assessment procedures as
defined in Phtlkin et al. (1989). Streams with
sunnned habitat assessment x'alues >80% of the
possible maximum score xvere used as refer-
ence streams; those xxith loxxer scores xxere con-
sidered test streams. In addition, other habitat
measures were quantified at each site. Specifi-
cally, xve calculated axei-age bank-full xxidths at
each study site from 5 transects 50 m ecjuidis-
tant. We estimated canopy coxier for the entire
reach (ca 250 m) and presented it as quartile
percent, i.e., 0, 25, 50, 75, or 100% coverage.
Substratinn size (.x-axis), embeddedness (quar-
ter system as for % canopy cover) xalues, and
xvater depth were measured from 100 randomlx
chosen stones (locations for depth) xvithin a
100-m section of each studx' reach. Using an
Orion (model 126) conductivitx^ meter stan-
dardized to 20 °C, xve measured specific con-
ductance in the field. Field pH was measured
xvith either an Orion (model SA25()) or Schott
(model CG 837) pH meter. Alkalinitx' and hai"d-
ness xvere quantified in the laboratory using
standard methods (APHA 1992). Nitrate and
phosphorus concentrations were measured
using a HACH meter (model DR2()0()) and
HACH reagents. Water xelocities for calcula-
tions of discharge xvere determined using an
OttC-1 meter

We collected periphxton by scraping all
material from a knoxvn area on the surface of
5 stones and transfeiring the material onto sep-
arate Whatman GF/F glass-fiber filters (n = 5/
site; after Robinson and Minshall 1986). Upon
filtering, the material x\'as kept frozen at -25 °C
until analysis in the laboratoiy for chlorophyll a
and AFDM. InitialK; xve ground samples in
reagent-grade acetone using a Brinkmiann tis-
sue homogenizer (model PT 10/35). Chloro-
phyll a xvas extracted in reagent-grade acetone
and quantified using a Gilford Model 2600
spectrophotometer (APHA 1992). Samples from

56

Great Basin Nail kalist

[Volume 58

1993 were extracted in 100% methanol; metha-
nol extraction eliminates the need to grind
samples (Holm-Hansen and Riemann 1978).
Although both extraction media result in simi-
lar extraction efficiencies, we conducted a test
to compare chloroph)]] a concentrations from
samples using both media, (.'hlorophyll a was
extracted from samples in acetone or methanol
and (luantilied as above. The results indicated
no difference between the methanol and ace-
tone methods (/; = 0.76, independent samples
t test, n = 20). Periphyton AFDM of each sam-
ple was determined as described above for
BOM (see below) using the remaining material
from chlorophyll a analysis.

Depending on the year of stud); we used
semiquantitative and quantitative collection
techniciues for sampling macroinvertebrates to
meet specific study objectives for that year In
1990 semiquantitative sampling was conducted
at all selected sites, and an additional 5 quanti-
tative samples were collected at 5 of these
sites. In 1991 and 1993 we completed quanti-
tative sampling at all selected sites, with addi-
tional semiquantitative samples collected at 10
of these sites in 1991. Benthic macroinverte-
brates were semiciuantitativeh' collected from
riffle/run habitats using a metal-framed net (1-
mm mesh in 1990 and 500-/xm mesh in 1991
and 1993, 30 cm high x 60 m wide x 100 cm
long) affixed to a D-style shoNcl handle. A 3-
min sample was proportioned among riffle and
run habitats along a 150-m length of stream
and presen'cd in the field with 10% formalin
(Plalkin et al. 1989; also see Resh and Jackson
1993). Using a modified Hess net (25()-^tm
mesh), we collected quantitative benthic sam-
ples at 5 riffle/run habitats at each site. Although
different mesh sizes were used between years,
no statistical differences were found between
respective biotic metrics at a particular site
(Robinson and Minshall 1995a).

Benthic organic matter was estimated from
material obtained in the (juantitatiNe macro-
invertebrate samples. Following removal of
macroinvertebrates, organic matter was deter-
mined by drying the sample at 60°C for at
least 48 h, weighing, ashing at 55()°C for 2 h,
rehydrating, redrying for at least 24 h, and
reweighing. The difference in dry weights was
the (juanfitx of organic matter (as AFDM) for
that sample. In the laboratory we systemati-
cally hand-picked a 3()()-count samjile of inacro-
invertebrates from each semi(|nanlil;iti\(' sam-

ple for metric analysis. In 1990 all macroinver-
tebrates were removed from each (]uantitati\e
sample. In 1991 and 1993 the 5 quantitatixe
samples from a site were combined and, fol-
lowing the initial removal of large and rare
taxa, a minimum of 300 organisms were sys-
tematicalK hand-picked from the combined
sample (analogous to the 2-phase sample pro-
cessing described by Cuffiiey et al. 1993; also
see Courtemanch 1996). We identified all
picked macroinvertebrates to lowest feasible
taxonomic unit (usually genus) and enumer-
ated them.

Biotic metrics were calculated from the
macroin vertebrate data from each site as
described in Winget and Magnum (1979),
Platts et al. (1983), Fisher (1989), Plafkin et al.
(1989), Chandler and Maret (1993), and Clark
and Maret (1993). Seventeen metrics were cal-
culated for benthic macroin\ertebrates: ratio of
Ephemeroptera, Plecoptera, and Trichoptera
(EPT) abundance to Chironomidae (CH) and
Oligochaeta (O) abundance (EPT/CH + O);
species richness; EPT richness; Hilsenhoff
Biotic Index (HBI); Biotic Condition Index
(BCI); ratio of EPT/CH; % dominant taxon;
Shannon's diversity index (H'); Simpson s dom-
inance index (C); ratio of shredders to total
macroinvertebrate abimdance; macroinxerte-
brate densitv; % scrapers; % filterers; % shied-
ders; % EPT taxa; % CH+O; and % Chirono-
midae. The HBI used an assigned scale of
0-10 (Hilsenhoff 1988) and regional tolerance
\ alues from Clark and Maret (1993).

I'or the 25 sites e\aluated in 1993 in the
N1{M, we calculated macroin\ertebrate met-
rics from iMsher's (1989) data due to budget
limitations. Fisher (1989) assessi'd 1.'37 sites in
the NRM, data which the State of Idaho
wanted to incorporate into their biomoniloring
program. For (|ualit\ assurance, wt- collected
macroinvertebrates from 4 of these sites and
compari'd biotic metrics for macroinx erte-
brates with respectixe data from Fislu-r (1989).
Althcmgh some discrepancx' existed in identifi-
cation of taxa (Fisher consistentK' had higher
species richness and EFF richni'ss \ alues), most
otlii'r biotic metiics appeared robust iMiongh to
mitigate the diff(Mi'nces. l-oi- iwample, higliK
similar \alues wcri' lonnd loi" % EPT and %
CH+O. liased on these results, wc felt confi-
denl that metrics could be calculated for all 25
sdcams using Fisher s data in concert with our
liabital measures, 'lb eliminate discrepancies in

1998]

BlOASSESSMKM Ol" lUAlK) SII^IlAMS

57

richness values, we eonibined some olnious
"split" taxonomic tiroups, e.g., Baetis species.
Specimens of all macroinvertebrate taxa col-
lected (luring the stucK' were retained lor
Noucher collections and housed at the Stream
Ecology Center of Idaho State University; Poca-
tello; Idaho Department of Health and Wel-
lare. Bureau of Laboratories, Boise; and Orma
I. Smith Museum of Natural Historx; Albcrtsou
College of Idaho, Caldwt'll.

We completed separate nuiltiple discrimi-
nant anaKses (MDA) using (luantitatixc habitat
measures, biotic metrics, and relatixc abun-
dances of die most common tiixa or ta.\()nomic
groups to determine variables that best differ-
entiated reference and test streams in each
ecoregion (Tabachuick and Fidell 1989). Some
taxa were combined at the generic (e.g., Ephc-
mcrcUa) or family (e.g., Elmidae) level to pro-
\ ide enough data for statistical comparisons; all
combined tiL\a had ecjual tolerance \alues (after
Clark and Nhiret 1993). These ta.\onomic groups
generalK' comprised over 80% of the macro-
invertebrate assemblage at any one site. One-
way ANO\'A was used to determine differ-
ences in (juantified habitat variables of refer-
ence sti^eams among ecoregions; variables were
tiansformed prior to anaKsis to improve data
homoscedasticit>- (Zar 1984). Following MDA,
we scored selected l)iotic metrics for each
ecoregion similarh' to methods described in
Barbour et al. (1996). Briefly, metrics that had
values greater or lesser (i.e., dependent on par-
ticular metric) than the median \alue of refer-
ence streams scored 5, those between the
2o9ci\c (or 75%ile) and the median scored 3,
and those higher than the 75%ile or lower than
the 25%ile scored 1. We then summed indixid-
ual metric scores for each site to pro\ide an
o\erall score for that stream. Separate t tests
were performed to test for differences between
average reference and test site scores within
each ecoregion (Zar 1984).

Re.sults

Habitat Assessment and
Environmental Conditions

As designed, reference streams had higher
a\ erage habitat assessment values (after Flafkin
et al. 1989) than test streams in each ecoregion
(Fig. 1). Indeed, reference sites had average
\ alues 60 points greater than test sites in the
NBR and SRF and 30 points more in the

R T

Northern

Rocky
Mountain

Fig. 1. A\era,tic ( + l.v) hal)itat asscssineiit \aliies (after
Plalkin et al. 19<S9) for reference and test stri'anis within
each ecoregion.

NRM. However, NBR and SRP test streams
displa\'ed a wide variation in habitat assess-
ment values that ranged from <30 to 143 (144
was the separation value for reference and test
streams). Because of design constraints (see
Methods), test streams in the NRM showed
much less variation and had higher average
habitat scores than test streams in NBR and
SRP ecoregions.

Multiple discriminant anaKsis using (juanti-
fied habitat measures clearh' separated refer-
ence streams in each ecoregion (Fig. 2). Refer-
ence streams in the NRM were distinguished
from other reference streams by lower eleva-
tions and lower water temperatures (Root-1),
whereas reference streams in the NBR and
SRP had similar elevations and temperatures
but differed significantK' in water chemistiy
and width;depth ratio (Root-2). Here, refer-
ence streams in the NBR liad higher ionic
measures (e.g., specific conductance, alkalinity,
and hardness) and greater depths (i.e., differ-
ences in width :depth ratios due to differences
in depth not width) than streams in the SRP
(Table 1).

There were some major differences in habi-
tat characteristics between reference and test
streams within each ecoregion; these differ-
ences were especially evident in the NBR and
SRP Ph\sicall\, test streams typically had lower
gradients, more open canopies, smaller sub-
strata, higher substrata embeddedness, and
higher water temperatures than reference
streams (Table 1). Chemical differences among

58

Great Basin Natur^vlist

[Volume 58

CM 5

o 2'

o ~ 0

oc S

(F=5.01,p<0.000)

"" Root-1

(elevation, temperature)

Fig. 2. Multiple discriminant analysis scatterplot of root
scores for individual reference streams within each ecore-
gioii based on quantitative habitat measures. Circles inde-
pendently drawn to illustrate differences among ecore-
gions.

stream types were most evident in the NBR,
with test streams showing 2x higher ion con-
centrations than reference streams. In addition,
pliosphoriis concentrations were ca 2x greater
in test streams than in reference streams, al-
though they were more pronounced in the SRP
eco region. Again, few differences were observed
in habitat conditions between test and refer-
ence streams of tlie NRM, although test streams
did display higher water temperatures than
reference streams (Table 1). Differences in
biotic resources were less evident among test
and reference streams due to high variability
(e.g., all CVs > 100%). However, there were
some trends of enhanced periphyton standing
crops in test streams relative to reference
streams. For example, average chlorophyll a
levels were 4x greater in test streams than in
reference streams in the NBR, and pcripin ton
AFDM values were 3x greater in test streams
than in reference streams in the SRl^ fhese
patterns are contrary to those in the NRM and
may reflect a reduction in brxophxtes (not
(luantified in this study) in test streams in this
ccorcgion (d.T. liobinson personal obsenation).

Macroinvx-rlebratc Assi'ssnicnl

Multiple discriminant anaKsis (MDA) re-
vealed important but different metrics for dis-
tinguishing between reference and test streams
within each ecoregion (Table 2). For example,
only KFV richness was an imporlanl disciiuii-
nator between stream types in all ecoregions.

Metrics found important for distinguishing
stream types in the NBR included EPT rich-
ness, EPT/Chironomidae ratio, 9c H\dropsy-
chidae, % scrapers, % EFf titxa, % CH + O, aiid
% Chironomidae. Important metrics lor the
SRP included taxa richness, EFT richness, HBI,
EPT/CH + O ratio, % dominant taxon, % filter-
ers, and % EPT taxa. Thirteen of 17 metrics
were deemed important in the NRM (Table 2),
but this high number probably reflected the
less degraded conditions of test sites in this
ecoregion. MDA results (i.e., root scores for
individual sites within each ecoregion) are
shown in Figure 3. This t\'pe of presentation
simply demonstrates that (1) most reference
sites were biologicalK' different from test sites
(outliers also were evident), and (2) variation in
biotic metrics occurred among streams.

MDA based on individual taxa indicated
that different taxonomic groups, except the
Elmidae, were important for distinguishing
among stream types in each ecoregion. Four
taxa differentiated reference and test sites in
the NBR: Elmidae, Heptageniidae, JjipcuhL
and Ephemerellidae (Table 2). For the SliH
these taxa included the Elmidae, Rhvacopliili-
dae, Brachycentrus, Capniidae, Dniiwlla,
Turbellaria, and Simuliidae, whereas Baetis,
Elmidae, Zapada, Brachijcenirus, DniiicUa, and
Simuliidae were important discriminators in
the NRM ecoregion. The graphical presenta-
tion of site MDA root scores shows clear sepa-
ration between reference and test streams but,
as with the biotic metrics, a high variation in
taxonomic properties among stndv sites within
each ecoregion (Fig. 4).

Correlation analysis was used to reveal
rediuidant metrics or taxonomic groups from
the MDA results. Of these metrics and taxa,
those having the least amount of overlap
between ri'ference and test sites were retained
lor devc'lopniiMit of a biotic assessment score.
'Iwo nu'lrics and no taxa v\ere eliminated from
the NRB: EPT/C:hironomidae ratio and ^f
Cll+O (Table 2). Onlv taxa richness and
Drimclld v\ere omitted in the SRI! whereas
taxa richness, EPT/Cll+O ratio, '( dominant
taxon, Shaimon's index, % (lli + O, and '''( (Chi-
ronomidae were removed from score develop-
ment in the NRM (no taxa vNcre eliminated in
the NRM). Lower, albeit nonsignilicant. biotic
metric and ta.xonomic scores were lonnd lor
lest sites relative to reference sites in the \RI{
(metric, /; < 0.15; taxa, p < .15) and SRP

1998]

Bioassessmi>:nt()K Idaho Sthkams

59

TABLt: 1. Plnsical, chemical, and resource cliaracteristics for reference (R) and test (T) streams exaluated in eacli
ecoregion. Cliaracteristics expressed as means, standard deviations (Std), and coeflicients ol variation (CV). Blank cells
wi're sites in which that \arial)le was not recorded. Xari.iMcs tint are underlined showed siiiniiieant dillerenees lutween
reference and test streams in the NBR or SHH

Nortlu'rn

Basin and R

ange

Snake

Ri\t'r Plain

Northern

Rock-)- Mouii

tains

Mean

Std

(:\

\l(Mn

sul

(A

Mean

Std

(A

PnvsicAi,

liieNiition (m)

K

175(i

1.35

8

16.30

612

38

1131

298

26

I'

irw)

228

13

1586

355

22

1.329

409

31

Slope (%)

W

4.1

3.3

80

.3.7

3.5

94

3.3

1.4

43

V

l,(S

1.0

65

1.8

1.2

71

2.3

1.4

63

Discharge (m^/s)

n

0.1.5

0.64

141

0.12

0.08

67

0.23

0.17

75

■\

n.M)

0.33

111

0.23

0.25

111

0.29

0.20

71

Irinpfniturc (C)

H

11.2

3.3

29

12.6

4.0

32

7.5

2.6

35

T

15.1

3.3

22

15.7

4.2

27

9.7

2.6

27

Wultli liiii

R

3.8

1.2

32

3.4

1.4

43

6.0

2.4

39

T

.3.5

2.0

56

5.1

2.4

48

6.3

3.0

47

Wullli (Icptll T.itio

R

l.S.B

8.1

44

21.1

7.5

36

.33.9

14.2

42

T

16.3

7.1

43

25.6

8.5

33

25.7

13.9

54

CanopN ctncr {%)

R

4(i

26

56

67

20

30

40

31

76

T

Ifi

22

137

28

33

118

39

32

82

Substrata size (cm)

R

15.0

7.2

48

15.8

4.9

31

31.6

13.9

44

T

7.3

6.5

88

9.4

5.2

55

31.2

11.7

37

Eiiibeddedness {%)

R

34

6

19

27

12

45

25

11

43

T

51

14

28

42

21

51

22

6

29

Chknucai.

Specific conductance (umhos)

R

131

112

85

114

56

49

70

40

58

T

288

146

50

117

66

57

58

22

38

AlkalinitN-dng/LCaCO^)

R

62

53

86

45

27

60

41

19

46

T

138

59

43

59

25

43

36

16

45

Hardness (me/LCaCO.)

R

88

57

65

48

30

63

T

190

61

32

66

32

49

pH

R

8.2

0.4

.5

8.2

0.4

5

8.0

0.4

.5

T

S.4

0.2

3

7.8

0.6

8

7.7

0.1

1

Nitrate (mg/LNOj)

R

11.(19

0.06

69

0.07

0.03

48

T

0.07

0.03

49

0.08

0.06

75

Phosphorus (mir/LPO,)

R

0.06

0.04

57

0.13

0.13

101

T

0.10

0.11

106

0.26

0.23

86

BlOTIC RE^SOLRCES

Benthic oriianic matter (g/m^)

R

127.2

240.1

189

22.9

19.4

85

T

76.8

95.1

124

46.5

82.8

178

Pcriphyton clilon>pli\ll a

R

7.1

8.5

120

15.6

17.7

113

45.3

47.3

104

finft/cm-)

T

28.3

64.7

229

18.1

23.8

131

22.8

13.8

61

Pcnplntiiii \KDM (iiiii/ciii-

R

24.1

43.5

LSI

12.6

27.8

221

66.9

41.2

62

T

10.1

10.9

108

.39.1

86.1

220

72.4

24.5

34

(metric, /; < 0.10; taxa, p < 0.13) ecoregions,
whereas respectixe metric scores were essen-
tialK identical in the NRM (metric, p < 0.51;
ta.\a, p < .79; Fig. 5). However, combining
scores from metrics and taxa caused reference
sites to ha\e significant])' greater average
scores than test sites in tlie NBR ij) < 0.02
with 2 outliers removed) and the SRP (p <
0.01), indicating inclusion of ta.\onomic metrics
proxided additional important biotic informa-
tion on stream condition. The 2 outhers in the
NBR actual!) had habitat assessment scores of
142 and 143, very close to the arbitrary separa-
tion score of > 144 for reference streams, sug-

gesting this biotic scoring technique is robust
for assessing stream conchtion.

Discussion

The priman' goal of the study was to exam-
ine a series of abiotic and l)iotic metrics for
assessing biological integrit> in 2nd- to 4th-
order streams within the NBR, SRI^ and NRM
ecoregions of Idaho. Collecting these baseline
data from reference or "best case" streams and
degraded systems allows the development of
biological criteria for each ecoregion for use
b\ resource managers. In general, the same

60

Great Basin Natur.\list

[\()Iume 5(S

Tabi.e 2. MDA factor coefficients for metrics and titxa found significant for discriminating; between reference and test
sites within each ecoregion. Separate analyses were completed for metrics and specific taxa within each ecoregion. Val-
ues ill hold indicate redundant metrics omitted from scori' dcxelopment for that ecoregion 'see Methods).

Metric xariahle

Northern
Basin and Range

Snake
River Plain

Northern
Hock\' Mountains

Tiixa richness

EPT richness

HBI

BCI

EPT/C;hironomidae

EPT/Chironomidae +

Oligochaeta
% dominant taxa
9c Hydrops\chidae
Shannons
Simpsons
% scrapers
% filterers
% shredders
% EPT taxa
% Chironomidae +

Oligochaeta
% Chironomidae

1.39

-1.47

0.82

-2.46
-0.36

-0.90

-1.13

2.41
-0.37

1.37
-0.78

-1.27

-2.78

0.45

-2.37
-3.59

-2.31
1.07

-0.86
2.24
4.78
.5..56
1.11

0.78

1.56

-0.87

Ti

Lxon \ariai)ie

Bcu'tis

Elmidae

Ileptageniidae

Zapada

Rhyacophilidae

Brarlu/ccntnis

Ephemerellidae

Hexatoma

Capniidae

DruHcUa

Turht'llaria

Sialis

Sinuilidae

0.61
0.91
-0.58

-0.49

.01

1.28
0.48

-0.30
-0.81

0.85

0.75

-2.42
0.49

1.86
-0.25

1.23

-1.43

(liialit;iti\(' liabitat asses.sment measures can be
used for evaluatinjj; hal^itat quality in each
ecoregion. However, additional research is
needed to test whether these differences in
(|ualitati\'e measures are associated with land-
scape-scale changes and iu)np()inl souice pol-
lution in Idaho (see, e.g., Kichards et al. 199{i).
In contrast, some (juantitative variables loi
assessing a(iuatic habitats are important lor
distinguishing among stream types within and
among ecoregions. These measures max belter
reflect gross changes in landscape properties
that arc not exidcnt in (|nalitati\c habitat assess-
ments l)ut more relevant to a(|nalic biota. I'oi
e.xample, measiu'cs oi nia.ximnm water temper-
ature, substrata si/e, specific conductance, and
nutrients provide important additional inlor-
mation to explain diflerences in habitat eoiuli-

tions among streams within an ecoregion that
also are indicatixe of dominant land uses or
nonpoint source pollution. Further, although
ionic concentrations tend to be higher in de-
graded streams, this finding is more exidcnt
lor streams in the \BH than in tln' SHI' (the
rangi' in habitat assessment xalues is similar in
both ecoregions). Mean chlorophxll a xahu's
also are 2-4x higher in degraded siti's than in
rclcrence sites in the NBK and SUP t'core-
gions, but the high xariability among sites loxx-
ers the importance of this lactor lor assc\ssing
a(|natie habitats. Our results suggest the impor-
tance ol iiielnding additional (luanlitalix e nu'a-
suic'S, xxater ehemistry in particular, in habitat
assessment protocols to mori- fullx' describe
enx ironmental conditions ol a stream (Ki'sli et
al. 1995). ( Current technologx alloxxs rapid and

1998]

BlOASSESSMENT OF IdAIIO STREAMS

61

(0

<D

^.

O

o

CO

o
o

<

o
o

3 1
2

1

0

-1

-2

-3
3 n
2
1
0

-1 ^

-2
-3
-4
6
4
2
0
-2
-4
-6

fli

rJl

NBR

fl

SRP

n

NRM

n

D

Reference

Test

Fi<4. 3. Histogram of multiple (liscriininant aiuiKsis root scores for iiulixielual streams within each ecoregion based on
biotic metrics. Dotted hiie separates reference from test streams. Note tlie \ariatioii amoiiii stri'ams within each ecore-
gion.

accurate field determination of general tlun il-
eal cliaracteristics and temperature regimes for
aquatic .systems, which at times can o\erride
the importance of other habitat measm-es in
constraining benthic populations.

Macroin vertebrate metrics derived fiom EPT
taxa, measures of dominance, abundances of
chironomids, and HBI are important for distin-
guishing among stream t>pes in each ecoregion.
Ho\\e\er, tlie relati\'e importance of some biotic

metrics also differs between ecoregions. For
example, Chironomidae and Oligochaeta are
predominant in the XBR, suggesting that met-
rics based on these organisms are important
for discriminating among stream t>pes in this
ecoregion, whereas % filterers is important in
the SRP These findings Anther demonstrate
the necessity of a multi-metric approach to
develop and refine biological metrics for spe-
cific regions of the country or a state to account

62

Grkat Basin Natuiulist

[Volume 58

^ -3

-4

O

E
o

c
o

X
(0

I-

(0

0)

o
o

o
o

<

Q

i

n

r

NBR

.n

_ oD D__

n

u y ^

rjp WW'W

-

,y^ i

-■

J

2 -
1

0 -1

>

0) .2

n

Ul

nD

n

SRP

n

u

NRM

u

TJ

Reference

nu

Test

FiK- 4. Ilislof^rain ol iniiltii)l(' clisciiniiiiaiit analysis roof scores lor iii(li\ idiial strcains within each ccori'Uion liascd on
taxononiic {groups (sec Methods). Dolled hue sepaiales icleicnec Ironi tcsl streams. Note the variation anionu streams
within eacli ecorej^ion.

for the natural rej^ioual variation observed lor stream types 1)\ iiuliuliiiu incasiin's based on

lotie systems (Hughes et al. 1990). Ho\ve\er, the most abinKJaiil la.\a, (.'xeliidinu eliiroiioinids

readers are direeted to Harbour et al. (199(i) lor and oliuoebaetes. Results indieate some taxa.

an alternative approaeli tliat applies a dilleren- as grouped b\ lamily (low abundanees pre-

tial seorinj^ regime for usinjj; llie sami' biolie eluded use ol some indixidiial ta.xa in nmlti-

metrics amon^ reji;ions. \aiiale statislies), to be espeeialK sensitixc for

We examined the potential ol additional eharaeteri/inii; stream t\pes (also see liesh and

macroinvertebrate metries to dillerenliate L n/ieker 1975, Minshall 1996). For e.xample,

BioASSEssMiAi ()i Idaho Siki.ams

63

50
40
30
20
10
0

0)

NBR

o

T
o

2 60

8 - ! SRP

R

50

O

■^ 40
O

bo 30
Q)
> 20 ^

o

0)

60

50 ]

40

30

20

10

O

R

o

T
o

o

o

o

o

o

R

R T

Metric

R T
Taxa

o

NRM

o

-Q-

O

_

O

i

t=^ :

o h

O

J_ :

O

R T
Both

Fig. 5. Box plots for summed metric scores of reference and test streams within each ccoregion tor hintic metrics and
taxonomic groups separateK; and combined metric and taxa scores. Each Iiox jilot represents the niecUan, standard de\ia-
tion, and 90% confidence Umits; open circles are outliers.

that .some faniiK' groups are more abiiiulaiit in
referenee (e.g., Eliiiidae, Heptageniidae, and
Rhxacophilidae) than in degraded streams
affirms that certain taxa max be especialK' good
indicators of habitat or \\ater cjualitx'. Other
tiLxa are abundant enough at the genus le\el to
compare among stream t\pes: Hexatoma, Drii-
nellcL and Brachyccntnis. The inclusion of tdx-

ononiic metrics, whether at the famiK; genera,
or species lexel, greatl\- improxes die informa-
tion content and biological rele\ ance of proto-
cols designed to assess lotic integrity (e.g.,
Robinson and Minshall 1995b).

In simimaiA. different metrics proxe impor-
tant for assessing ecological conditions in
streams from different ecoregions in Idaho.

64

Great Basin Natur.\list

[\'()lume 58

The use of indixidual inetrics also prox ick'S
important information concerning the kinds of
pollution, or changes in the t) pes of pollution
or land use, affecting a particular water hocK.
For example, similar types of land use may
show different effects on streams among ecore-
gions because of regional differences in abiotic
and biotic properties. Lastly, assessing the bio-
logical integrity of streams is complex and
re(|uires multiple measures that can elucidate
the diverse causes of ecological impairment.

Acknowledgments

A number of indi\ iduals assisted in the suc-
cessful completion of this project: D.M. Ander-
son, J. Check, T. Curzon, ED. Dey, R. Gill, E
Koetsier, D.E. Lawrence, J. Mann, J. Mihuc,
T.B. Mihuc, S.C. Minshall, G.C. Mladenka,
D.C. Moser, C.A. Nelson, J.S. Nelson, M. Over-
field, S.E. Relyea, TV Royer, K. Sant, S.A.
Thomas, and J.T Varricchione. We thank T
Koch, S. Langenstein, M.J. Mclntyre, M. Ing-
ham, E Olmstead, C. Corsey, S. Grunder, B.
Smith, and A. Van Vooren for information on
prospective field sites. We appreciate the help
of J. Mende, D. Earrish, and F Fartridge of the
Idaho Department of Fish and Game for assis-
tance at various times during the project, and
the use of Fisher's (1989) benthic data from
streams in the Northern Rocky Moimtain eco-
region. B. Smith, USFS-Salmon NF made pos-
sible the selection and sampling of streams in
the Fanther Creek catchment. Special thanks
go to WH. Clark, R.T Litke, M. Mclntyre, M.j.
McMasters, and 13. Zaroban of Idaho Depart-
ment of Health and Welfare, Division of Envi-
ronmental Quality, and T.R. Maret of the United
States Geologic Suivey for adxice and assistance
throughout the project. The stud> was funded
through a grant from the Idaho Department of
Health and Welfare, Division of Environmental
Quality. We appreciate the constructive com-
ments from TV Royer and 2 anonymous re-
viewers. 'I'his paper is dedicated to the memory
of I3r 'i'imothy Litke.

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index: integrated biological, physical, and chemical
stream parameters for management. /;i. Aquatic
ecosystem inventorv': macroinvertebrate analysis.
U.S. Forest Service Intermountain Region Contract
No. 40-84-M8-8-524, Brigham Young Universitv;
Provo, UT

Zar, J.H. 1984. Biostatistical analvsis. 2nd edition. Pren-
tice-Hall, Inc., Englewood ClifTs, NJ.

Received 18 December 1996
Accepted 2 September 1997

Great Basin Naturalist 58(1), © 1998, pp. 66-75

BATS OF THE WHITE AND INYO MOUNTAINS
OF CALIFORNIA-NEVADA

Joseph M. Szewczak'-, Susan M. Szewczak^, Michael L. Morrison^ and Linnea S. Hall^*

Abstract. — We surveyed l)ats throughout the White and Inyo Mountains of Cahfornia and Nevada. From Deceniher
1990 to November 1996, we surveyed hibernating bats, and foraging bats from June 1992 to September 1996. The
White-Inyo Range rests in a unicjue biogeographical junction between the Sierra Nexada, Moja\c Desert, and Great
Basin regions. Elexational grachents of 305-4.340 m, coml:)ined witli limited human development, further enhance tlie
interest of natural historv' and fauna! distributions in this range. We found 13 bat species in the course of 2668 obser\a-
tions. Three of these species, the spotted bat {F.uderma tnaculafinn), silver-haired bat (Lamomjcteris noctiva<ians), and
hoary fiat (Lafiiunifi cinereius), have no previous records from the White-Inyo Range. We found bats in all vegetation
zones except the alpine, 3500-4342 m. Despite an abundance of mines in this range, only Townsend's big-eared bat
{Conjnorhinus toivnsendii) and the western small-footed myotis {Mtiotis ciliolahnim) used them routincl\. Our data also
indicated the importance of surface water to bat populations in arid regions.

Kctj words: bats, Chiroptera, Great Basin, ve^,etation zones, hahiiat. desert, arid regions, water source, hibernation.

The White-Inyo Range rest.s in the junction
of 3 faunal regions: the Sierra Province to the
west, Mojave to the south, and Great Basin to
the east. Because this range rises abruptly on its
east and west sides, animals can readily access
a variety of vegetation types over short linear
distances. In addition to altitudinal differences,
vegetation communities are enhanced by a vari-
ety of edaphic sites resulting from the range's
high lithographic diversity (Elliot-Fisk 1986).
Despite this interesting biogeographical setting,
faunal distributions of the range have received
little attention. Morrison et al. (1993) pnnided
the first thorough study ol bird distributions
and habitat use in the White-Inyo Range.
However, no systematic survey of bats and
their habitat associations in these mountains
has been undcrtakcu. Hock (19b3) sununarized
results ol a handful of general collecting trips
from 1917 to 1958 that yielded some bat speci-
mens. This sinnmary plus an unpublished
manuscript from a field course at Unixcrsity of
C>alif()rnia at Davis (Brosius et al. ca 1974) con-
stitute all prior records.

Our objectives were to pioxidc a dclailcd
accouut of bat distributious throughout ihc
White-Inyo Range, assess how each species
utilizes the different vegetalion /ones axaiiablc
to it along the range's elexafional gradient, and

characterize how each bat species uses a\'ail-
able mine resources. We report observations
from both foraging and hibernating bats.
Because the White-Invo Range remains lela-
tively undisturbed habitat, this baseline ma\
prove useful for tracking long-term alterations
in environment, since many researchers con-
sider bats to be sensitive indicators of en\ iron-
mental change (Kunz 1982, McCracken 1986,
Thomas 1988). These data also provide useful
comparisons for other ranges in the region.
Thousands of abandoned mines lie on public
and private lands (Shields et al. 1995). The
importance of these mines as reserxoirs for
wildlife displaced from natural habitats has
gained increasing recognition (Tuttle and Ta\-
lor 1994), and docinnenting patterns of mine
use by bats in the W^iite-lnxo Range ma>'
prove useful for present and future manage-
ment efforts.

Study Ahka

The White and In>() Nh)untains extend h)r
appro.\imatel\' 175 km, forming a contiguous
laiigc (lending iu)rtli-s()uth and 1\ ing just east
of and parallel to the- Sierra Nexada. 'I"he W'hiti'
Mountains c'onii)ris(' the northciii hall, located
within Inxo and Moiu) lonnties, ( iaiiloinia.

'University of California Wliilf Mounlaiii Kcsfarcli M.idnn. :!()()() r...sl l.im- SI , liislio|>, ( :A H,r>l 1

^Author lo wlioin torrcspondi-ncc slioiild lie addrcssi-d

■'Oi-[)ar(inriit of Hiolonical .Scifnws, Califoniia Stale lMi\(isil>, Saer.iineiilo. ( .A O.'iMO

m

1998]

Bats of iiii, Wiiiii-iwo Ra.\(;i£

67

and extcndinti into Esmeralda C^ounh. Nt'\ada,
on their northern reaeh. The Inxo Monntains
extend to the south and he entire!) within ln\ o
Count}, Cahfoniia. Eknational gradients span
from 300 m at the eastern base of the Inxo
Moimtains in Salim- \alle\, ('ahfornia, to the
4342-m summit ol \\ hite Nh)imtain I'eak. (]ah-
(ornia. Annual preeipitation \aries houi less
than 10 eiu at the liase ot the range to api)n)\i-
mateK 50 cm along the northern crest of the
White Mountains (Oglesln 1985, Peterson
1986). The Owens and Chalfant \alle\s (Cali-
fornia) fonn a continuous valley separating the
range from the Sierra on the west, while the
east side of the range descends into a series of
\ alleys. From north to south they are Fish Lake
\alle\', located within California and Nevada,
and Deep Springs \'alle\. Eureka Valley, and
Saline \'alle>, all within ('alifbrnia. Although
we centered this suney on the \\ hite-lnyo
Range, to fulfill our goal of assessing eleva-
tional range we elected to extend our suney of
foraging bats into the \alle\' floors at the base
of these mountains. Bats foraging in these
areas ma\- depend upon rocky outcrops and
other features of the mountains for roosts and
hibernaculae.

Fi\ e priman^ vegetation zones occur in the
White-Inyo Range along elevational gradients:
(1) Mojave mixed desert scrub, characterized
by the presence of creosote bush (Larrea tri-
dentota), 300-1200 m; (2) Great Basin desert
scrub, where shadscale {Atriplex confertifolia)
is the most common species, 1200-2000 m; (3)
pin\on-juniper forest, predominantK" single-
leaf pinyon {Piniis monopJujUa) interspersed
with Utah juniper {Jimiperas osteosperma),
2000-2900 m; (4) bristlecone-limber pine for-
est (or subalpine), a mixture of these 2 trees
{Pinm lungaeva and Pinus Jlcxilis), 2900-3500
m: and (5) alpine, characterized b\' the absence
< )t' trees, 3500-1342 m.

Methods

Foraging Bats

We considered bats on the wing fiom Ma\
to October to be foraging. Although actixe bats
are occasionalK seen during fair winter weather
(Barbour and Davis 1969), these flights may
not necessariK' be for foraging (Whitaker and
Rissler 1989). We sune\ed throughout the
range in all \egetation zones between June
1992 and September 1996. .Although we often

could obser\e bats foraging o\er open vegeta-
tion aw a\' from water, we could seldom capture
such indi\ iduals. Therefore, most of our cap-
tures occurred at sources of water that
attracted bats (springs, pools, troughs, and
stream corridors). We assume these records
ic-present bats obsened foraging in the vicinity
( )l those water sources.

Foraging bats wxm'c captured over approxi-
niatcK 200 person-da\'S in the field from Ma\
through October 1990-1996. We used mist
nets or a harp trap set across open flyways near
water sources. Four bats recorded in this study
were hand-captured from buildings at Deep
Springs College, Inxo Coimt), (>alifornia. We
keyed each specimen to species (Ingles 1965,
Barbour and Davis 1969, Hall 1981), deter-
mined gender (and reproductive status if
female), and then released it. We txpicalK
maintained the nets from dusk to local 23:30 h
depending upon activit}; which normally trailed
off around 22:.30 h. OccasionalK; we maintained
nets throughout the night but made few addi-
tional captures.

Although troublesome to differentiate in
other regions, M. ciliolahnim and M. califonii-
ciis were readily distinguished in the White-
Inyo Range. The White-Inyo M. ciliolahnun
has a distinctive straw-colored pelage with a
highK' contrasting dark facial mask and ears.
The M. califoniiciis we encountered has a chest-
nut brown pelage with much less contrast to
the facial mask and ears (Barbour and Davis
1969, Hall 1981).

We also recorded bats we could identify
without capture. In 2 instances, with the aid of
binoculars, we identified roosting Brazilian
free-tailed bats (Tadarkhi hrasiliensis). We then
counted indi\iduals as the\' emerged in the
evening. We similarK' assessed a colon\' of pal-
lid bats {Antrozous pullidus). The audible calls
of the spotted bat {Eiidenna maculatum) enabled
species recognition without specialized ecjuip-
ment and supplemented capture records for
this species.

Hibernating Bats

We considered inacti\e bats between the
mondis of XoN'ember and March to be hiber-
nating. From December 1990 to November
1996, we surveyed 2 natural ca\es and approxi-
mateK 260 mines for hibernating bats, working
approximateh^ 125 person-da>'s in the field. We
entered the mine or ca\e and xisualh' inspected

68

Gri-:at Basin Naii kalis r

[\blume 58

all accessible reaches, pa> iiij; particular atten-
tion to crevices in the walls and ceilings. We
took care to minimize disturbance to bats and
other inhabitants In limiting direct light con-
tact and moving (juietly through the mine or
cave. Species determinations were made by
noncontact inspection to avoid disturbance.
FortunateK; all species were identified easily
in this way. M. cilioluhnim was often found
5-10 cm deep in crevices but was recognizable
b\' its size, pointed tragus, straw-colored fur,
and almost black facial mask (Barbour and
Davis 1969, Hall 1981). Using a mercun' field
thermometer ±1°C accuracy, we recorded air
temperature in the immediate vicinity of roost-
ing bats.

Previous Capture Records

We searched for previous capture records of
White-Inyo bats at the Los Angeles County
Museum of Natnral Histoiy (LACM), Museum
of Vertebrate Zoolog)' at Berkeley (MVZ), West-
em Foundation of Vertebrate Zoology (WFVZ),
and among the holdings of the University of
California White Mountain Research Station.
We included these records in our tabulation of
obser\'ed species and range distributions.

Results

We encountered a total of 13 bat species
from 2668 observations during our sui-vey
(Table 1). Three species, E. tnaculattiin, silver-
haired bat {Lasionycteris noctivagans), and
hoaiy bat {Lasiunis cinereus), were not previ-
ously recorded in the White-Inyo Range. The
little brown bat (Mt/otis hicifiigiis) had 1 prexi-
(nis record from this range (LACM); we did not
encounter it in our survey (see Mi/otis i/uiiki-
nensis comments in Discussion), although it is
known in the nearby Sierra (Hall 1981). T.
hi'dsilicnsi.s, E. uiaculalwn, Townsend s big-
cared bat {Con/nurliimis town.sendii), A. pal-
lidus, western pipistrelle {Pipistrelhis licspc-
n/.s), big brown bat {Eptesiciis fitscus), long-
legged myotis {Mi/otis vohnis), and western
small-looted myotis {Myotis ciliolahntin) were
all loimd in both the White and Inyo xVlonn-
tains portions ol the range. L. nociivaginis, L.
cincrciis, long-eared myotis {Myotis cvotis),
and (>alil()rnia myotis (Myotis californicus).
however, were loimd only in llic \\ liilc Moun-
tains portion ol the combined rangi'. M. yiniid-
ncnsis was found only in the Invo .Mountains.

Tabi.K L C^oiiipilftl ()l)scnati()ns ol' l)ats in tlif W'hite-
In\() Kaii,t;c\ 1990-1997, witli previous records shown in
parentheses. Previous specimen number for Mtjuti.s lolans
is inexact, as it was described as "man\ from 3 locations
(Museum of Vertebrate Zoologx).

Number

Number

ol)ser\ed

obsened

Species

foraging

hibernating

Tudarida Imi.silieiisis

1185 (.5)

—

Eudcniia inticiihifiiin

91*

—

ConjiiorJiinu.s toicnsciidii

45 (2)

479 (1.3)

AntrozDits ])allklwi

85 (4)

—

Lasiom/ctcri.s noctivcif^ans

2

2

Lcifiitiriis cinereus

27

—

Pipi.strellus hespenis

410 (18)

4

Eptesiciis fuscus

100 (4)

1

Myotis evotis

12(3)

—

Myotis voldns

103 (14-I-)

1

Myotis caUfttniicus

15(2)

—

Myotis ciliolabnim

33(4)

49

Myotis lucifiifiiis^

(1)

—

Myotis yuiiKniensis-^

24(3)

—

TCJTALS

2132 (60+)

,536(13)

*Tlirci' captured in mist nets. otluT records from acoustic detection; see text.
+\\'e lia\e not listed M. lucifiigiis described In I jams (1974); see text.

We found bats in all xegetation zones e.\cept
alpine (Fig. 1). The Great Basin desert scrub
zone had the highest species richness with 13
species, including the LACM M. litcifiigus
record. Pinyon-juniper was the next richest
zone, wherein we recorded 10 species. We re-
corded 9 species in the Mojave mixed desert
scrub zone. We found onl\' 3 species in the
bristlecone-limber pine zone; of those 3, onK"
E. fuscus and M. volans w t-re obsened forag-
ing in the zone, whereas C. townscndii was
recorded hibernating.

The single richest site survexed was the
lower portion of Cottonwood C'reek where it
enters Fish Lake Valley aboxe the Oasis Hanch
on the east side of the \\'hite Mountains (T5S
R37E, Sec 33; 1600 m elevation). At this site
we captured 12 species on separate occasions:
T. hrasilicnsis, E. mdcithitiiiiL C. toinisrndii, A.
ixillidiis, L. iioclirdgdiis. L. ciiKniis. P. hespenis,
E. fuseiis, M. voldns, M. ((dijornieiis, M. eilio-
l(d)ruiii, and M. evotis. The most pro(lucti\c>
night at this siti' was 15 .Vugusl 1995, during
which 20 7' hrdsilieiisis, I /•.". iiideuldtuiit, I A.
pdllidus. I L. eiiiereiis, 1.) /' liespents, 9 E. fus-
cus, 2 M. voldns, and 1 M. ciliolahruni were
mist-nellcd dniing a 2-Ii jieriod.

i)es|)ilc an abmulanci' ol carbonate locks
lliiougliout the- \\ hiti'-ln\() Kange, onl\ 1 ca\ -
(III is known (2090 m). Located near Westgard

1998 J

Bats oftiii; W iiiii;-I\M) IU\c;k

69

2,000

I

Mojave mixed
desert scrub

foraging range
H^H hibernating range

Tadarida brasiliensis

Euderma maculatum

Corynorhlnus townsendll

Antrozous pallidas

Lasionycterls noctivagans

Lasiurus cinereus

Pipistrellus hesperus

Eptesicus fuscus

Myotis evotis

Myotis volans

Myotis californicus

Myotis ciliolabrum

Myotis lucifugus

Myotis yumanensis

i'l. 1. Ele\;iti()iial clistril)uti()ii of ion

4,000
'

elevation in teet
6,000 8,000

10,000
I

12,000

I

14,000

alpine

iiwiMiiiiiiiiiiiiiiiiiiiiiiii mil

i ;

1,000

2,000
elevation in meters

3,000

4,000

kI hilR'niating hats in the Wliite-lino Raii^e showing vegetation zones.

Pass, Ciilifoniia, this ca\ern extends approxi-
mate]) 50 111 inward with ceiling liei^hts np to
about 25 111. This ca\ern remains undisturbed
because it is protected b\- a locked gate and
remote location and is relatively inaccessible
because of its vertical entrance. However, fol-
low ing 4 \isits over separate xears, we obscned
onl\- a single C. townsendii hibernating within
it. A single C. townsendii was obsei^ved hiber-
nating in a 2-m-deep natural pocket in a dolo-
mite formation in the southern end ol the White
Mountains (1(S9() m). On 2 occasions (5 Decem-
ber 1991 and 18 Februaiy 1995), an active L.
noctii'a<ians was found in a domiitoiy hallway
at Deep Springs ('ollege. Because of their con-
dition and the dates, we assumed the\ had
been hibernating on the premises. All other
hibernation obsenations were from mines.

We found C. townsendii and M. ciliolahnnn
hibernating in mines throughout the range.
These species were obsen ed hibernating with-
in about 40 cm of each other. However, we
often encountered lone individuals of either

species within a mine. We never obsen ed M.
ciliolahnnn hibernating together, but C. town-
sendii were observed in clusters as large as
approximately 50 individuals. We observed onl\
1 individual each of £. fuscus, L. noctivagans,
and M. volans hibernating in mines. In mines
below 1500 m, we encountered bats in approx-
imately 25% of mines >3 m in length. Above
1500 m elevation, approximateK' 50% of mines
> 3 m in length contained at least 1 bat. These
estimates of mine use are based upon our gen-
eral impressions only, because it was not possi-
ble (or deemed safe) to enter eveiy mine, or to
survey eveiy part of the mines we did enter.

Species Accounts

Tddavidd brasiliensis

T. brasiliensis was found at the lower eleva-
tions of die lino Mountains and southernmost
portion of the White Mountains (lower Cotton-
wood Creek, above Oasis Ranch, Mono Co.,
California: T5S R37E, Sec 33; 1600 m). We

70

Gri£at Basin Natur.\list

[\bliime 5(S

obsen'ed a dispersed colony of 1028 at the
base of McElvoy Canyon on the east side of the
Inyo Mountains, Inyo Co., Cahfornia (640 ni).
We descril)e this colony as "dispersed because
they roost in a series of overhanging ledges
along the narrow canyon wall, rather than a
single site. A perennial stream flows through
the canyon below the roosts. We counted these
bats on 26 July 1992 as they flew overhead
after emerging, heading in the direction of
Saline Valley. This site appears vacant during
winter A crevice in a large boulder above the
Deep Springs dairy (Inyo Co., California; T7S
R36E, Sec 1; 1590 m) hosts more than 100 T.
brasiliensis for several weeks during the spring,
perhaps a stopover during migration. On 19
August 1996 we found a small colony at the
entrance of a dolomite mine at the western base
of the Inyo Mountains near the "shoreline" of
Owens Dr\' Lake, Inyo Co., California. We
could not detennine the number of bats in this
colony, but from the limited guano deposit and
apparent configuration of the crevice, perhaps
no more than several dozen were present.

Euderma maculatum

Three E. maculatum were captured along
lower Cottonwood Creek on the east side of
the White Mountains (Mono Co., California;
T5S R37E, Sec 33; 1600 m), 2 males on 17
August 1993 and 1 female on 14 August 1995.
Based upon audible calls of this species, we
found it to be a common forager among mid-
ele\ ation riparian corridors of the range down
to the Owens Dry Lake bed (Inyo Co., Califoi-
nia; west side of Inyo Mountains, 1080 m). We
would typically hear E. maculatum from
shortly after twilight until the early morning
hours. From April through October we rou-
tinely heard E. maculatum foraging over the
fields and buildings of Deep Sjirings ('ollegc
(Inyo Co., California; T7S R36E, Sec 1; 1600
m). The latest in the year this bat was heard at
Deep Springs College was 9 November 1996.

Corynurhinus tuwnsendii

Three foraging C. townsendii were cajitured
during this survey, 1 male in Queen Caiixon al
the northern end of the White Mountains on 9
July 1992 (Esmeralda CJo., Nevada; TIN B33lv
Sec 32; 2410 m), 1 male at Lower Cottonwood
Creek on the east side of the White Mountains
on 27 August 1992 (Mono (Jo., ( California; T6S

R37E, Sec 5; 1600 m), and 1 female on 25 July
1992 at a concrete water trough at the north-
west end of Saline \'alle\' Lake at 305 m (Inyo
Co., California; T14S R38E, Sec 27). We ob-
served 36 individuals exiting a maternity roost
at the base of the White Mountains in Deep
Springs Valley (Inyo Co., California; 1705 m),
and a single male carcass was found in a build-
ing at Oasis Ranch in Fish Lake Valley on the
east side of the White Moimtains (Mono Co.,
California; T5S R37E, Sec 28; 1530 m). A
maternity colony of several hundred is known
on the west side of the White Mountains, Inyo
Co., California (1710 ni; Patricia Brown-Beny,
personal communication). This bat is iilso known
to roost in laxa tube caves on the western slope
of the In\'o Mountains at approximateK' 1380
m (Denyse Racine, California Department of
Fish and Game, personal communication). The
remaining C. townsendii observations were of
hibernating individuals. Six bats were obsened
hibernating in a White Moimtain mine at 3188
m on 28 November 1992, the highest obsen'a-
tion of this sun'ey. The majority of mines we
entered during the winter months aboxe 1500
m harbored at least 1 C. townsendii. This bat
distributed itself well among the available
hibemaculae, rather than concentrating within

a few selected sites. The 7 largest concentra- j

1
tions observed (per mine) were 80, 51, 40, 25, I

25, 20, and 19 bats. The group of 80 was found

in the Inyo Mountains at 2140 m elevation

with an air temperature near the bats of 5°C on

12 Februar) 1995. The group of 51 was found

in the White Mountains at 2400 m elevation

and an air tenijierature near the bats of 4°C on

12 il'bruar\ 1994 (lino Co., CJalifornia). Seven

individucUs were found in a mine conipli'x on

the west side of the White Mountains on 25

February 1993 (Vlono Co., CJalitbrnia). We

obserxc'd these bats in a lower adit w ith an air

temperature near them of -.3°C.

Afilrozou.s jxillidus

We found .A. ]uilUdus al scattered locations
throughout the iii\o \h)nntaius bilow 1710 in
and as low as 430 iii al Saline \'alle\ I iol Springs
(Inyo Co., California; T13S R39E. Sec 18). Our
onl\' observations of this bat in tlu> White
\h)untaius occuned at lower CJottonwood C>reek
(\h)no Co., Califoniia; T5S R37E, Sec 33; 1600
m). rheri' is a nialernih roost in a side enlranic-
wa>' of the Deep Springs C>oIlege boarding-

1998]

Bais of tul: W hhe-Inyu IUxge

71

house (ln\() Co., California; 1600 ni) from w Iiicli
we counted 39 liats exiting on 5 y\ugust 1994.
liats. presuinahK fiom this colony, can often
he seen night roosting at \arions sites aroinid
the college dniing the summer This roost ii'-
mains \aeant duriuu (he w inter We captiiicd I
male and 1 female on hS June UWfi and
another female on 9 Jul\ 1996 on the eastern
shore of Owens Dn- Lake north of the town of
Keeler (In\o Co., California; T16S R38E, Sec
31; 1080 m).

L(isi())njctcri.s )i()rHi'(i<i,(in.s

We captuicd a male /.. n()ctiia<!,(iiis in the
White Mountains at the lower (>ottonwood
Creek site (Mono Co., California; T5S R37E,
Sec 33; 1600 ni) on 11 June 1996. A female L.
noctivas.ans was captured in a domiiton' room
at Deep Springs C'ollege (Inyo Co., California;
T7S K36E, Sec 1; 1600 m) on 8 October 1991.
On 5 December 1991 we obsened an indixid-
ual hibernating in a drill hole in a mine devel-
oped in dolomitie marble on the southern
slope of the \\'hite Mountains (Inyo Co., Cali-
fornia; 2050 m). Another indi\idual was cap-
tured in the dormiton wing of Deep Springs
College on 18 Februan 1995. From the condi-
tion of this bat and the time of year, it had
probabK' aroused from hibernating on site.

Lasiuru.s cincreus

We captured 1 female and 3 males at 2090
m along Chiatovich Creek (Esmeralda Co.,
Nexada; TIS R34E. Sec 29) on 6 July 1992,
and 17 females and 7 males at 1590 m along
Cottonwood Creek (Mono Co., California; T5S
R37E, Sec 33), both on the east side of the
W hite Mountains. Another male was captured
on 26 June 1992 along \\yman Creek at 1920
m on the southern reach of the W'hite Moun-
tains (Imo Co., California; T6S R36E, Sec 22).
These drainages all ha\"e stands of cottonwood
{Pupulus frcinontii), a large-leafed tree consid-
ered desirable to this tree-roosting species
(Barbour and Da\ is 1969).

Pipistrelliis hesperus

P. hespents is the most common bat we cap-
tured in mist nets. Most captures occurred
within the 1st hour after sunset. On 26 JuK*
1992 we netted 51 females and 37 males at a
pool in McElvoy Canyon on the east side of
the In\o Mountains in 1.5 h (Invo Co., Califor-

nia; T14S R37E, Sec 1; 790 m). W'e often ob-
seiAed this species emerging well before dark.
Om- highest elevation capture was a male on
22 JuK 1992 at 2740 m in Hie Inyo Mountains
at Mexican Spring (Inyo ilo., (California; ri5S
1-138 E, Sec 34). P. hespenis is known to be spo-
radicalK active throughout the winter (Bar-
bour and Davis 1969), and we obsened it in
the late afternoon and early exening fixing over
and coming doxvn to sip from the hot spring
pools in Saline Valley, east of the Inyo Moun-
tains, in Februan and March 1994 (Inyo Co.,
California; T13S R39E, Sec 18). Over the
course of 7 nights between 6 April 1996 and 18
September 1996, xve captured 30 P. hesperus
oxer small ponds on the eastern shore of
Oxvens Dr\ Lake near the toxxn of Keeler (Inyo
Co., California; T16S R38E, Sec 31; T17S
R38E, Sec 5; T17S R38E, Sec 22; all at 1080
m). Our 4 hibeniati(m obsenaticms of this bat
occurred at the loxvest mines xve sin-xexed
(1340-1400 m; Inyo Co., California). Air tem-
perature near the bats in these mines was
xvarmer (15°C) than temperatures xve encoun-
tered at higher elevations, a situation not ideal
for minimizing energy expenditure during tor-
por, but perhaps conducive to foraging during
occasional xvinter mild spells (Barbour and
Davis 1969, O'Rmell and Bradlex 1970).

Eptesiciis fusciis

We captured E. fiiscns along the loxver sec-
tions of perennial streamfloxvs of the White
Mountains. All drainages in xvhich we cap-
tured this bat xvere upstream from ranches
xxith established agricultural fields. Hock (1963)
listed this bat as occurring up to 3090 m in the
White Mountains. Unfortunatelx; we do not
k-noxv xvhether this refened to a hibernating or
foraging individual. On 26 June 1993 xve found
E. fusciis foraging along Lone Tree Creek on
the xvest side of the White Mountains at 2070
m (Mono Co., California; T3S R33E, Sec 33).
We found a single hibernating bat in a mine
tunnel in the White Mountains on 12 Februan^
1994 at 2500 m (Inyo Co., California). A stor-
age shed at Deep Springs College (Inyo Co.,
California; T7S R36E, Sec 1; 1600 m) serves as
a night roost for about 3 dozen of these bats;
hoxvever, the dax' roost location for this group
remains unknoxvn. On 16 August 1996 xxe cap-
tured a post-lactating female over a small pond
on the eastern shore of Owens Dry Lake (Inyo
Co., California; T16S R38E, Sec 3i; 1080 m).

72

Great Basin Natl iulist

[Volume 58

Mijotis evotis

We found M. evotis along the lower drain-
ages of the W'hite Mountains and up through
the pin\()n-jiiniper zone. Our highest eapture
for this speeies oecurred on 8 July 1993 at 2470
m along Chiatovich Creek (Esmeralda Co.,
Ne\ada; TIS R33E, See 35), where we cap-
tured 1 male and 1 female; however, the MVZ
lists a 1954 record from Cottonwood Creek
(White Mountains, Mono Co., California) at
2895 m. A female M. evotis was captured
beside a storage building at Deep Springs Col-
lege (Inyo Co., California; T7S R36E, Sec 1;
1600 m) on 4 September 1992. All other cap-
tures were at water sites.

Mijotis volans

M. volans was well distributed throughout
the White-Inyo Range in the Great Basin
scrub and pinyon-juniper zones. We obsei'ved
a single hibernating A/, volans during this sur-
vey in a mine at the north end of the White
Mountains on 31 Januaiy 1993 (Esmeralda Co.,
Nevada; 2770 m). Our highest foraging obser-
vation of M volans occurred at Mexican Spring
toward the southern end of the Inyo Moun-
tains at 2740 m (Inyo Co., California; T15S
R38E, Sec 34); however, the MVZ also lists a
1954 record of "many" specimens of this bat
from Cottonwood Creek (White Mountains,
Mono Co., California) at 2895 m. Our lowest
capture of this bat was a male netted on 25
August 1992 at a road stream crossing in Silver
Canyon on the west side of the White Moun-
tains at 1410 m (Inyo Co., Califoniia; TBS R34E,
Sec 24). On 19 June 1996 we captured a non-
reproductive female over a small pond on the
eastern shore of Owens Diy Lake neai" the town
of Keeler (Inyo Co., California; 1178 R38E,
Sec 5; 1080 m).

Myotis californicus

We captured A/, californicus at 4 sites in the
White Mountains along its Jowt-r slopes in the
Great Basin scrub zone and up into the begin-
ning of the pinxon-Jiiniper zone. On 24 July
1995 and 3 August 1995, a fc-male M. californi-
cus was found roosting during the day in a
classroom at Deep Springs (>ollege (In\() (-o.,
California; T7S R36E, Sec 1; 1600 m).'()n 25
August 1992 we captured a lemale at a road
stream crossing in SiKcr (Jan\'on on the wt'st
side of the White Mountains (Inyo Co., Cali-
fornia; T6S R34E, Sec 24; 1410 m) and 2 males

at the Lone Tree Creek headworks (Mono Co.,
Calilornia; T3S R33E, Sec 33; 2070 m), also on
the west side of the White Mountains. Three
other females were captured along the lower
portion of Cottonwood Creek on separate
occasions (Mono Co., California; T5S R37E,
Sec 33; 1660 m).

Myotis ciliolal)rnin

Together with C. townscndii, M. ciliolahrinn
was the only other bat we commonly tound
hibernating in the White-Inyo Range. Our
highest hibernating obsei-vation of M. cilio-
labriiin occurred on 12 Februaiy 1994 at 2500
m in the White Mountains (Inyo Co., Califor-
nia), and our lowest was on 23 December 1990
at 1710 m in a small mine on the northwest
slope of Deep Springs \alle\' (In\o Co., Cali-
fornia). We usually found this bat well up into a
crevice and hibernating alone, even among a
group of tunnels. However, we found 10 dis-
tributed through a mine in Marble Can>'on on
the east side of the Inyo Mountains (In>o Co.,
California; 2260 m). We found M. ciliolahrwn
foraging throughout the Great Basin scnib and
pinyon-jimiper zone of the range. Our highest
foraging observation for this species was a
male captured at Mexican Spring toward the
southern end of the Inyo Mountains on 22 JuK
1992 at 2740 m (Inyo Co., California; T15S
R38E, Sec 34); the lowest was a pregnant
female we captured over the runoff of a spring
on the eastern shore of Owens Dry Lake (T17S
R38E, Sec 9; 1080 m) on 30 May 1996.

Myotis lucifii<^ns

We did not encounter A/, lucijnpis during
our sune\, but the LAC>M lists a specimen of
M. lucifu^us from lower \\yman (>an> on in the
southern White Mountains from Ma\ 1972
(Inyo Co., California; T6S R36E, Sec 23; 1740
m). However, we believe a discrepancy exists
regarding the Myotis sjieeies in the Owens
Dr\ Lake area. Our conunents in this regard
are in the Discussion below.

Myotis ynnnntcnsis

We captured 24 spi'cimens ol this bat along
the eastein shore of Owens Dr\ Lake on the
southern end oltlic lino Mountains, The most
prolific aeti\it\ occurred o\or a small pond
se\-eral km north of the town of Keeler (In\o
Co., Califoniia; T16S R38E, Sec 31; 1080 m).
There we captured 8 lactating females and 1

1998]

Bats of tiii£ Wtute-Iwo IUxge

ra

xolant jii\ ciiilc male on 9 jiiK' 1996. At another
small poiitl closer to kcclcr, we captured 1 lac-
tatinu and 1 pregnant female on 19 June 199(i
(Inyo Co., California; TITS R3SE, Sec 5: 1080
m). These records indicate the presence of a
niaternitx roost in the Keeler vicinity. On 24
August 1995 we netted a female at the Sulfate
Well on Owens Dn Lake (In\() Co., California:
TITS K38E. Sec 18) and a male and a female
on 14 September 1995 near the eastern Owens
Lake margin (Inyo Co., California; T16S R3TE,
Sec 26). We also obseiAed these bats fixing to
foraging sites on the lake bed at dusk, presuni-
al)I\ heading out from roost sites east of tlie
lake, at the base of the ln\o Mountains.

Discussion

Of the 13 bat species we encountered in
this sur\e\, none specialized in any of the 5
xegetation zones of the White-In\'o Range. All
species o\ erlapped with at least 1 other zone,
although for L. noctivagans. L. cinereiis, and
M. calif ornicu.s die overlap from the Great Basin
desert scmb into die pinxon-juniper zone was
limited. E. maculutum, C. towmendii, P. Jiespe-
ni.s, E. fiiscus, and M. volans were all found
foraging over 3 zones. Including the hibernat-
ing obsen'ations, C. townsendii extended its
range through all zones in which we obsened
bats. We obser\ed onl\- E. fuscus and M. volans
foraging in the higher bristlecone-limber pine
zone, compared with 9 foraging species in the
pinyon-juniper zone. In contrast, Morrison et
al. (1993) obsened 61 bird species in the
bristlecone-limber pine zone, 3 more than in
the pinyon-juniper zone. The reduced bat for-
aging acti\it\' in the bristlecone-limber pine
zone nia\ result from the diunial \ s. nocturnal
liabits of birds vs. bats and these bats' exclusive
insect diet. The higher elevation of the bristle-
cone-limber pine zone elicits colder nocturnal
temperatures, causing impoxerished nocturnal
insect actix it\ (Wellington 1945). Graham (1983)
found a similar decrease in bat species moving
up an elexational gradient in the Pennian
Andes.

C. towmendii foraged in 3 different vegeta-
tion communities (Fig. 1). This bat is a known
lepidopteran specialist (Barbour and Da\is 1969,
Clark et al. 1993). While some lepidopteran
species nia\' be found tliroughout these \egeta-
tion communities, the overall species composi-
tion among these communities most likeK' dif-

fers. Successfully utilizing such different envi-
ronments as Mojave nii.xed desert scrub and
pinxon-junipcr forest suggests an ability to
exploit a \ariet\ of foraging strategies and prey
selection. Such adaptabilit\ ma\ seem surpris-
ing in \ iew of evidence that this species re-
mains threatened o\ t-r much of its original range
(former (>2 species and C^alilornia species of
special concern). However, this result is consis-
tent with other studies indicating that roost
disturbance may be a more decisive factor in
this bat's decline than habitat disturbance (Pier-
son and Rainey 1994). The remoteness and low-
human population density of the White-Inyo
Range reduce human disturbance as a factor.
Howexer, the remoteness of this range also
pro\ides relativcK undisturbed foraging habi-
tat; thus, the relatixe effect of roost vs. habitat
disturbance cannot be separated. In fact, the
situation in the \Vhite-In\'o Range could also
be interpreted to suggest that C. townsendii
requires undisturbed roosts and foraging habi-
tat to thri\'e. InterestingK; the modem White-
Inyo population of C. townsendii ma\' exceed
prehistoric numbers. Humphrey and Kimz
(19T6) concluded that this bat is a capable colo-
nizer It naturalK roosts in caverns, which
rarely occur in this range. Because of this, C.
townsendii has only recently begun roosting in
the area, basically within the many mines cre-
ated in the last centun.

We should note that om- sunex shows a bias
toward acti\"it> in riparian corridors and other
areas with water as those were the onK' places
in which we could effectixeK' capture foraging
bats. Widi diis bias, the comparative richness we
measured in the Great Basin desert scrub zone
niav instead depict the richness of a wetland
environment in the milder climate of this lower
elevation zone compared with the others. Thus,
it may not accurately reflect general compara-
ti\e trends in species richness in these zones.
Bats typicalK sip water b\ skimming over it
(Kunz 1982) and thus rec^uire water sources
with an open surface. We visited point water
sources in the Inyo Mountains with such con-
stant bat activity that we did not risk setting
mist nets too near them. Because such water
sources are the only ones available for many
kilometers in an\ direction, it seems clear that
entire populations depend upon these isolated
sources. We recommend that wildlife manage-
ment planners consider the impacts of such

74

Great Basin Natur\list

[Volume 58

water sources upon bats, in addition to other
wildlife. For example, the seemingK harmless
cessation of water flow to an old trough may
profoundly affect bat populations in a large
surrounding area. Exaluation of existing and
planned water sources with consideration of
bat needs could do much to enhance bat popu-
lations in arid regions.

Overall, C. toicnscndii and M. ciUolahnnn
accounted for nearly 99% of all bats found in
mines, with C townsendii comprising about
89%. Because both E.ftiscus and M. vokins are
regarded as regular mine users (Tuttle and Tay-
lor 1994), the single hibernation sightings for
these bats contrasted with our foraging obser-
vations of these species. This indicated that
either their White-Inyo hibernaculae remain
undiscovered or diey tvqDically leave the area to
hibernate. Our observation of L. noctivagans
hibernating in a mine is of note because this
species has rarely been found to use mines as
hibeniaculae (Barbour and Davis 1969, Alten-
bach and Pierson 1994).

Noticeably absent from this sui-vey was M.
hicifugiis, whose range is described as encom-
passing the White-Inyo Range (Hall 1981).
Perhaps the sparse timber of the range does
not meet the requirements of M. lucifugus,
which is described as preferring timbered areas
(Hall and Kelson 1959). The LACM record fiom
lower Wyman Canyon may be representative
of occasional forays this species may make into
the White-Inyo Range from the Sierra Nevada
to the west. The thoroughness of the present
survey would have likely encountered this
species if it routinely inhabited the White-
Inyo Range.

The Owens Lake nixotid that we recorded
as M. ijwnanensis is described by Harris (1974)
as the subspecies M. lucifugus relictus, with
Keeler as the type location. However, consis-
tent with earlier descriptions but contrarx to
Harris, we prefer to maintain its designation as
M. Ijwnanensis l)ased upon the dull and pale
pelage and light-colored ears characleiistic ol
M. Ijwnanensis, and our field obserxations in
which its habitat and foraging behaxior are
more consistent with M. ijwnanensis than with
M. lucifugus. The Keeler/Ovvens Dry Lake
locale is unforested, an uncharacteristic habitat
for M. lucifugus. From our obsenations these
bats foraged almost exclusi\'el\' ovi'r the scat-
tered open water along the margin of Owens
Dr\' Lake, flying just oxer it, a strategx' tx'jiical

of A/, yunianensis (Barbom- and Daxis 1969,
Herd and Fenton 1983). Harris s conclusion
xvas based solely upon 10 museum specimens,
a "few" study skins, and specimens in alcohol.
"Few specimens of M. I. relictus are undam-
aged, resulting in a less than ideal sample size
for statistical analx'sis. Hairis, noting the pale
coloration of the Keeler specimens, accounted
for it bx stating that "selection at the lower ele-
xations could easilx' have produced the lex'el of
paleness seen at Keeler." Lending further con-
fusion. Hams identified 3 of die 10 Owens Lake
museum specimens as M. ijwnanensis. What-
ex'er the taxonomic resolution of this debate,
all bats we recorded as M. ijwnanensis are a
morphologically similar population. A defini-
tive resolution of the species designation for
this population max' await DNA analysis.

M. thijsanodes (fringed myotis) xvas also ab-
sent fi'om this surv ey but has a range described
to include the White-Inyo Range (Hall 1981).
Barbour and Daxis (1969) described M. thij-
sanodes as preferring pinxon-juniper forests,
making their absence from the White-Inyo
Range more conspicuous. Hoxvexer, Hall and
Kelson (1959) mentioned that it does not seem
to be common anywhere in its range and that it
seems to prefer caves, xvhich seldom occur in
the range. Thus, in contrast to C townsendii.
which has apparentlx' mox-ed into the range by
exploiting many axailable mines in place of
natural caves, M. thijsanodes max' not lie as
adaptable to mines or max" mox(> more sloxxly
into prexiouslx unused areas.

More than a dozen bat species inhabit the
White-Inxo Mountain Range, attracted bx a
xarietx' of natural and artificial conditions. Oui'
data indicate influences in species distribution
from xegetation zones, axailability ol xxati'r, and
mines. Further work using noncontact census
methods will be required to assess the impact
of vi'getation zones axvax' from xxater Txlax the
\\'hite-lu\() Range senes as a refuge for bats,
and careful management of xxafer nn'nes, and
other resources max eontiuuc' this lole indeli-
uifelx.

ACKNOWll.ncXlKNTS

We could no! Iiaxc completed the scope of :
this surxcy xvilhoul the inxaluabic support ol [
Kathx Noland and the Inxo National i'ori'sl, I
Teiix liussi and the l^mcaii ol Laud .Manage-
ment, and l"'lizab(-th Phillips and Daxc Trx'dahl

1998]

Bats ()!• iiii; W iiiri:-l\i() H\\(;e

75

and the Uni\'er.sit>' of California \Miito Moini-
tain Research Station. NN'e thank 2 anonN uioiis
reviewers for their insights that eontril)iitecl to
the inannseript. \\e also acknowledge Alex
Heiger, Da\ id Calhraith. Noah llannn, and
Brendan Taatfe, and thank them lor their lu-li^.

LllKK.Vn KK CVYED

AlTKNBACH. J.S.. AND E.D. PiKRSo.N. 1994. Pages 7-18 in
The importance of mines to bats; an oveniew. Bats
and Mines 1994 Workshop Proceedings, Biological
Resources Hesearch ('enter. I'niMTsily of Nevada.
Reno.

Bahboir, R.W. and W.I I. Davis. 1969. Bats of America.
L'ni\ersit>' of Kentuck>- Press. Lexington. 2<S6 pp.

Bhosrs. \.G.. G. Erwin, \. Glickkn, P Kimsey, and
T. NIEI.SEN. \o date (ca 1974). A wildlife survey of
the White and In\o Mountains. Unpublished manu-
script, L ni\ ersitv of California, Da\is. L'nnuml)ere(l.

Cl\rk, B.S., D..M. Leslil- , Jr., and TS. Carter. 1993. For-
aging activity of adult female Ozark big-eared bats
(Plecotit.s townseiulii ingens) in summer, journal of
Mammalog\- 74:422—427.

Elliot-Fisk, D.L. 1986. Quateman cKnamics of the White
Mountains. Pages 47-50 in CA. Hall. Jr, and D.j.
Young, editors. Natural histon- of the White-Inyo
Range, eastern California and western Nevada, and
high altitude physiology. White Mountain Research
Symposium, Vblume 1, University of California, l.os
Angeles.

ClUII.vvi, G.L. 1983. Changes in bat species di\ersit\ along
an elcxational gradient up the Peni\ian Andes. Jo\ir-
nal of .Mammidog) 64:5.59-.571.

Hall, E.R. 1981. The mammals of North .\iiierica. 2nd
edition. \\'ile\, New York. 1181 pp.

Hall. E.R., and K.R. Kelson. 1959. The mammals of
North .America. Volume I. Ronald Press Co., New
York. 625 pp.

11 \RRIS, .\.H. 1974. Myotis yuinancnsis in interior soutli-
westem North .Vmerica, with conunents on Myotis
lucifuiiu-s. Journal of Mammalogy 55:.589— 607.

Herd, R.M., and M.B. Fenton. 1983. .\n electrophoretic,
nioiphological and ecological investigation of a puta-
tive h\brid zone between Myotis lucifugits and M.
yiimanen.si-s (Chiroptera: Wspertilionidae). Canadian
Journal of Zoologv 61:2029-2050.

H(k;k. R.J. 1963. Mammals of the White .Mountain Range,
California. White Mountain Research .Station Pul)li-
cations, Berkelev, C.\. 5 pp.

1 1 1 \IPIIREY, S.R., andT.H. Kun7.. 1976. Ecologv' of a Pleis-
tocene relict, the western big-eared bat (Plecotiis
townsendii), in the southern Cireat Plains. Journal of
Mammalogy 57:470-494.

In(;les, L.G. 1965. Mammals of the Pacific States. Stan-
ford University Press. Stanford. C\. .508 pp.

Ki \/, T.H. 1982. Ecologv ofbats. Plenmn Press, New York
and London. 425 pp.

-McCr.vcken, G. 1986. Why are we losing our Mexican
free-tailed bats? Bats 3:1-4.

MoRRLsoN, M.L., L.S. Hall. J.J. Keane, A.J. Klen/i, and
J. Verner. 1993. Distribution and abundance of birds
on the White Mountains, California. CJreat BasiTi Nat-
uralist 53:24(3-258.

O'Farrell, M.J., and W.G. Bradley. 1970. Activitv pat-
terns of bats over a desert spring. Journal of Mam-
malogv- 51:18-26.

OglesBY, R.J. 1985. AnaKsis of winter-season precipitation
totals and variations across the White Mountains
region of California-Nevada. Unpublished research
paper. University of (California. Davis, Geographv'
Department. 15 pp.

Peterson, A.M. 1986. The distribution and ecology of
deciduous tree species in the White .Mountains,
CA-.NY. Unpublished master s thesis, Universitv' of
California, Davis, Geographv' Department.

Pierson, E.D., AND W.E. Rainey. 1994. The distribution,
status, and management of Towsend s big-cared bat
{Corynorhinus toicnscndii) in California. Report to
California Department of Fisli and Game.

Shields, D.J., TC. Brown, and D.D. Brown. 1995. Dis-
tribution of abandoned and inactive mines on national
Forest Service lands. US DA Forest Service General
Technical Report RM-GTR-26(). 195 pp.

Thomas, D.W. 1988. The distribution of bats in different
ages of Douglas-fir forests. Journal of Wildlife Man-
agement .52:619-626.

Tlttle, M.D., and A.R. Taylor. 1994. Bats and mines.
Bat Conservation International, .-Vustin. T.X. 42 pp.

Wellington, W.G. 1945. Conditions governing the distri-
bution of insects in the free atmosphere. Canadian
Entomologist 77:7-15.

Whitaker. J.O., Jr., AND L.J. RissLER. 1989. Do bats feed
in winter? .\merican Midland Naturalist 129:200-203.

Received 18 March WfJ6
Accepted 14 Julii 1997

Great Basin Naturalist 58(1), © 1998, pp. 76-81

HABITAT USE BY SMALL MAMMALS IN SOUTHEASTERN UTAH,
WITH REFERENCE TO MEXICAN SPOTTED OWL MANAGEMENT

Maite Siireda'- and Michael L. Morrison^ '^

Al3STR.\CT. — We determined temporal and spatial differences in abundance and habitat use by small mammals in
southeastern Utah as part of an effort to enhance management of the Mexican Spotted Owl (Strix occidentalis lucida],
listed by the federal government as threatened. Woodrats [Neotoma spp.) were captured only in canyons and most fre-
quently in the pinyon-juniper {Piniis eduUs-Juniperus osteosperma) vegetation t\'pe. White-footed mice {Peroinyscm
spp.) were found in a variety of vegetation types in both canyons and mesas. The deer mouse (P. manicidatiis) was gener-
ally the most frequenth' captiued species among vegetation types. We found seasonal and yearly differences in relati\e
abundance of each small mammal species. Our data suggest that the pinyon-juniper vegetation t\pe within can\ons is an
important component of Mexican Spotted Owl habitat.

Key words: small duiiiiiiuiIs. habitat use, Ufali, rodents, Mexican Spotted Oicl.

Since its federal listing as a threatened
species in April 1993, several authors have re-
ported on habitat requirements of the Mexican
Spotted Owl (Ganey 1994, Zwank et al. 1994,
Ward and Block 1995). It has been suggested
that Mexican Spotted Owls select habitats
based partially on the availability of prey (Ward
and Block 1995). Confirming this theory is
vital for the owl's recovery; however, we know
of no published studies examining the distri-
bution and abundance of predominant prey
species within the range of the Mexican Spot-
ted Owl in Utah. In southeastern Utah these
owls occur >75% of the time within canyons
and <25% of the time on mesa tops (Willey
1992); the\ forage primariK' in the pinyon-
juniper {Piiiiis ediilis-litnipcnis osteo.s])cnmi)
vegetation type within canyons (Willey 1992,
unpublished data).

Our ol)jecti\'e was to determine spatial and
temporal differences in abundance and habitat
relationships of small manunals in canyons
and on mesas of the Manti-LaSal National
Forest in southeastern Utah. These data can
then be used to aid in managing and recover-
ing the Nh'xican Si)()tl('(l Owl in I fall.

SiuDV Ai{i:a

We condiicfcd our sfiid\ on flic Nh)ntic('!l()
l^angcr Disfrict of llic \Iaiifi-l.aSal National

Forest, San Juan County, Utah. The area, con-
sidered part of the Canyonlands Section of the
Colorado Plateau geographic proxince (Thorn-
bury 1965:417, 426), ranges from ele\ations of
approximately 1830 to 2680 m. Elk Ridge, the
dominant topographic feature of the studx' area,
is flanked to the west and east b>' steep-walled
canyons, 3 of which (Texas, Hammond, and
Dark can\'ons) contain Mexican Spotted Owls
(Willey 1992) and are the focus of our stud>'.
The study area comprises extensi\e sandstone
canyonlands, stair-step benchlands, allu\ ial \ al-
leys, high plateaus, and laccolithic mountains
(Barnes 1978).

Vegetation types sanipletl in our stud\ area
were selected based on their predominance
within can\()ns and on mesas. Within canyons
the following \egetation types were sampled:
(1) pinyon-juniper woodlands, (2) mi.xed-moun-
tain brush (Gambel oak \Qnvrcus ^amhclii].
alderleaf mountain-mahogau) [Ci'rcocarpiis
tiioiitatnis], and Utah serviceberr\' [Amclaii-
cliicr tifaheusis]), (3) riparian (willow |Sa//.v|
spp., grasses, and forbs), and (4) mixed-couiler
(ponderosa pine [Piniis potulcrosdl, whifi' fir
\Ahi('s C()tiC()l()i-\, and Douglas-fir {Psciidotsiif^d
iiicuzicsii]). We sampled .) \i'getafion txpes on
mesas: mature pondi'iosa pine, aspen- ({[uak-
ing asjiiMi [Popitltis troitloidc.s]) ponderosa
pine, and giass/loib-slniib.

'Wildlife- and Rslifrifs .Sticiurs. School ol Hciicwalilc Natural Ucsourics. I iiiv<isit> ol Aiiwina. Tiiisoii. .\'/. K5721.

^Present address: 20290 Jaiiieslowii Kd. # 12. Sonoia. CA 9.5.370.

•'Presfiil address: DeparliiienI of liioloKical Sciences, C;alifornia State l'Mi\crsit\, Sacraimiito, (:.\ U.'iSUJ.

76

1998]

Small Mammal IIabiiat Usi-:

77

Mktiiods

Sniall-iiianinial trapping grids were located
raiidoniK witliin acti\ it\ areas of 3 owl home
laiiges in Texas, llaniniond, and Dark canyons;
aeti\ it\ areas were delineatc-d following Wil-
le\ (unpul)lislied data). Trapping grids were set
within each ol the predominant vegetation
t\ pes in ean\()ns and on mesas surronnding
lach canxon. Becanse canxon width \aried
from approximateK 100 to 300 ni, to fit a giid
completeK' within some of the designated can-
xon M'getatiou types, we used grids of \arious
IciiUths and widths. IIowe\er, we arranged
them to approximate as nearh' as possible a 5
X 5 trapping pattern; all mesa grids were 5 x 5.
\\'e separated all trapping stations hy 15 m.

We trapped during 2 seasons for 2 yr, sum-
mer and fall 1994 and 1995. Summer trapping
was done fiom Ma\- through earK August, fall
trapping from late August through October. In
1994 we trapped 35 grids in each season (5
grids/vegetation t\'pe; 20 grids in canyons
[Hammond and Texas canyons], 15 grids on
mesa tops). In 1995, 28 grids were trapped in
each season (3—5 grids/canyon xegetation t)pes,
4 grids/mesa vegetation types; 16 grids in can-
yons [Hammond, Texas, and Dark canxons], 12
on mesas). A grid from each vegetation t\pe
was trapped sviichronously during a sampling
session to lessen temporal biases in results.
Each trapping period ran for 4 nights. O Fiir-
rell (1974) found that the moon had a negatixe
effect on nocturnal rodent actix itx'; therefore,
we trapped onl\' on nights around a nexx moon
(10 nights before, 10 nights after).

We placed 2 Sherman live-traps at each
tiapping station, alternating placement of extra-
large (10 X 12 X 37-cm) traps at each trapping
station xvithin each grid, so that 13 trapping
stations consisted of 1 extra-large trap and 1
large (7.6 x 8.2 x 22.9-cm) trap and 12 trap-
ping stations consisted of 2 large traps. All traps
contained poKester batting and \xere baited
xxith rolled oats and peanut butter (Davis 1982).
Extra-large traps increased the probabilitx of
capturing xxoodrats.

\\'e set traps before sunset and checked them
at sunrise. Upon capture, all mammals were
identified to species, aged, se.xed, xveighed,
and indixiduallx identified b\' toe-clipping.
We differentiated betxveen juxeniles and adults
1)\ pelage coloration, and we recorded repro-

ductixe condition as nonreiiroduclixc, abdom-
inal testes, or nipples.

We estimated relative abundance of pre-
dominant prey species as catch-per-unit effort,
defined as the number of captures per 100
trap-nights. Trap-nights xxere defined as the
number of traps per night multiplied b\ the
number of nights in the field minus sprung-
but-empty traps (Mills et al. 1991).

We made the folloxx ing comparisons of rel-
atixe abundance of each species: (1) separately
for canx ons and mesas between years, between
seasons bet\x'een years, and between seasons
xxithin x'ears; (2) for canyons versus mesas
xxithin years and for each season within each
xear; and (3) between vegetation types sepa-
ratelx' for canxons and mesas for each season
xxithin each xear These analx ses proxide infor-
mation on temporal and spatial differences in
species abimdance and habitat use. We used a
Mann-Whitney test (Zar 1984:138-146) for
comparisons of relative abundance of predom-
inant prey species between 2 groups. For com-
parisons between more than 2 groups, such as
between vegetation types, the Kruskal-W^tillis
test (Zar 1984:201-202) xvas used. If a signifi-
cant difference was found between vegetation
t>pes, we used Dunns test (Zar 1984:200) to
determine where the difference occurred.
Because of violations of assumptions, xve did
not conduct parametric analyses, and we
avoided multix ariate analyses because of low
sample sizes for some comparisons (exploraton^
multivariate analyses indicated no substantial
differences in interpretations xvith analyses
presented herein). P < 0.01 was used for sig-
nificance because of repeated 2-way compar-
isons; results at 0.01 < P < 0.05 were discussed
as tendencies toxx aid significance (exact Ps are
provided to aid in interpretation of results).

Results

Species Composition

During 25,148 trap-nights we captured a
total of 2906 new animals. White-footed mice
[Peromijscus spp.) were the most frequently
captured species group (81.2% of all captures),
of which 75.0% were deer mice {P. manicula-
tits), 11.7% canyon mice (P. crinitiis), 10.0%
brush mice (P. hoylii), and 3.3% pinx on mice
(P. triiei). Woodrats {Neototna spp.) were cap-
tured only in canxons and represented 1.9% of

78

Great Basin Natur.\list

[V'olume 58

all captures, of which 80.4% were Mexican {N.
mexicanus), 14.3% white-throated {N. alhi^ula),
and 5.4% Inishy-tailed (iV. cinerea) woodrats.
The montane vole {Microtus moiitamis), least
chipmunk {Tamias minimus), Colorado chip-
munk {T. qiiadrivittatiis), rock squirrel {Sper-
)n()pliilii.s V(irii'<i(itiis), silky pocket mouse {Per-
opKitliii.s flavus), western han^est mouse {Rci-
tliruduntoniys megalotis), ord kangaroo rat
{Dipodomys ordii), and a shrew species [Sorex
spp.) represented 16.9% of all captures.

Seasonal and Yearly Variation

Relative abundance (see Table 1) of deer
mice on mesas was significantly greater in fall
1995 than fall 1994 (P = 0.01, Mann-Whitney
[M-W]) and in fkll 1995 than summer 1995 (P

< 0.0001, M-W). Relative abundance of deer
mice in can\ons tended to be greater in sum-
mer 1994 than summer 1995 (F = 0.04, M-W).
Relative abundance of canyon mice in canyons
was significantly greater in 1994 than 1995 (F

< 0.0001, M-W) and in fall 1994 than fall 1995
(F = 0.0001, M-W), and tended to be greater
in summer 1995 than summer 1994 (F =
0.0250, M-W). Relative abundance of brush
mice in canyons was significantly greater in
1995 than 1994 (F < 0.0001, M-W), in sum-
mer 1995 than summer 1994 (F < O.OOOl, M-
W), and in fall 1994 than summer 1994 (F =
0.0001, M-W). In canyons relative abundance
of Mexican woodrats tended to be greater in
summer 1995 than summer 1994 (F = 0.04,
M-W) and was significantK' greater in fall 1994
than fall 1995 (F = 0.005, M-W) and in fall
1994 than summer 1994 (F = 0.0013, M-W).

Canyons Versus Mesas

The deer mouse was significantly more
abundant on mesas during 1995 (F = 0.0001,
M-W; 'fable 1). fhe canyon mouse and pin\{)n
mouse were signiticanth more abundant in
cauNons during 1994 (F < 0.0000, F = 0.007,
rcspcctJNcly, M-W; Table 1), whereas the brush
mouse was significantly more abundant in can-
yons the next year (F < O.OOOO, M-W; Tible 1).

The deer mouse had a significantly higher
relative abundance on mesas during sunuiui
and fall 1995 (F = 0.0 KiS, F < O.OOOl, respec-
ti\ely, M-W; 'fable 1). 'Ihe can\'on mouse had a
significantK higher relative abundance in
canyons during sunnner 1994 (F = 0.0007, M-
W; Table 1). The canyon mouse was captured

onl\^ in can>ons in fall 1994 and sunnner 1995,
and only on mesas in fall 1995 (Table 1). The
brush mouse had a significantK' higher rela-
tive abundance in canyons during fall 1994 (F
= 0.0007, M-W) and during summer and fall
1995 (F = 0.0010, F = 0.0021, respectively,
M-W; Table 1). The Mexican woodrat was cap-
tured only in can\'ons (Table 1).

Mesa Vegetation Types

We observed a tendency' for differences in
relative abundance of deer mice within mesa
vegetation types during summer and fall 1994
(F = 0.017,'f = 0.031, respectively, Kruskal-
Wallis [K-W]; Table 2) and fall 1995 (F = 0.05,
K-W; Table 2). Due to large variances in abun-
dance numbers, we could not detennine where
the differences occurred in statistical analyses
of multiple comparisons. Upon visual exami-
nation of mean indices, we determined the
grass/forb-shrub vegetation type had a higher
relative abundance of deer mice than the aspen
or ponderosa pine vegetation types. Canyon
mice, brush mice, and pinyon mice were cap-
tured veiy infrequently on mesas, and we cap-
tured no Mexican woodrats on mesas.

Canyon Vegetation T\pes

We observed a tendenc\' for differences in
relative abundance of brush mice between
canyon vegetation types in fall 1994 (F =
0.021, K-W; Table 2). Visual examination indi-
cates that the pinxon pine and mixed-moun-
tain biush M'getation t\pes had a higher rela-
li\e abundance of brush mice than did the
other \egetation types. \Ve obser\ed signifi-
cant differences in relative abundance of
l)iny()n mice in fall 1994 (F = 0.005, K-W) and
summer 1995 (F = 0.01, K-W). Statistical anal-
yses of multiple comparisons could not deter-
mine where the difference occurred due to
large \ariances in abundanci' numbers. Msual
examination ol mean indices shows tluit the
pinyon-juniper Nc-getation t\ pe had tlu> high-
est relatixt' abundance ol pinyon mice in both
seasons (Table 2). \Ve obserxcd no other signif-
icant dillerences in relatixc abundance of other
s|)('C'ics widiiu canNoii \ t'UclMlioii types. Mexi-
can woodiats were captured 4S.9% ol the time
in pin\on-juniper within canyons, whereas
24.4% were capturi'd in mixed-mountain brush,
22.2% in the riparian l> pe. and S.9% in mixed-
coniler.

1998J

SMAI.I. M \\1\I \I, I 1 MUTAT USE

Table 1. Small manimal rt'lativi' ahnndance (no. animals per 100 trap-nights) estimates in caiixons an
Manti-LaSal National l-'on-st. L tali, chninu; snnnnei and fall 1994 and 1995.

79

nu'sas of the

1994

1995

Sunnni'r

1

all

Ovei

■all

Sunnnri-

I

•all

Ovei

:-aIl

Species

.V

.V

.V

,S'

.V

.V

.V

.V

X

,S'

.V

.V

Deer mouse

Mesas

8.7

5.18

6.1

6.62

7.4

5.99

7.9

4.43

13.0

6.40

10.1

5.81

( ;an\ons

5.7

2.41

7.1

6.07

6.4

4.62

4.0

2.67

5.0

3.04

4.6

2.82

( Canyon mouse

.Mesas

<U.l

0.1 ;3

0.0

0.0

0.09

0.0

<().l

0.17

0.0

0.11

Canyons

2.2

2.41

3.7

4.12

3.0

3.42

1.2

2.19

0.0

0.7

1.69

Hrush mouse

Mesas

0.1

O.IS

<0.1

0.13

0.1

0.15

0.5

1.62

0.3

0.56

0.4

1.25

{^anxons

().]

0.37

1.4

1.46

0.4

0.82

3.4

2.51

2.6

2.08

2.7

1.42

Pin\ on mouse

Mesas

0.1

O.IS

0.0

0.0

0.13

0.2

0.44

0.1

0.22

0.1

0.36

Caiivons

0,4

1.07

0.3

0.49

0.4

0.82

0.4

0.91

1.0

1.83

0.7

1.42

Mexican woodial

Mesas

0.0

0.0

0.0

0.0

0.0

0.0

( lanyons

0.2

0.59

0.7

0.75

0.4

0.72

0.3

0,38

0.3

0.32

0.2

0.32

Other species

Mesas

l.S

2..50

1.5

1.91

2.3

1.68

2.8

1,95

3.7

3.26

4.5

2.49

C'an\ons

O.fi

0.8,3

0.6

0.91

0.6

0.86

1.3

1,48

2.1

1.76

1.8

1.65

Discussion

The deer mouse was generally the most
irequently captured species in all vegetation
types surveyed, which is consistent with its
general habitat associations (Burt and Gros-
senheider 1976, Hoffmeister 1986, Fitzgerald
ct al. 1994). Fitzgerald et al. (1994) noted that
w here habitat-specific Peromijsciis spp. occur,
(leer mice will be locally scarce or absent. This
was not the case in our study, where in most
vegetation types deer mice were consistent!)
more abundant than any other Peromyscus spp.
However, Armstrong (1979) noted that it is not
unconmion for Perouu/scus species to co-occur
in areas of heterogeneous vegetation, as are
found within canyons in our study area. For
example, the ini.xed-conifer vegetation type
within cauNons ma\' ha\e scattered pin\()n
pines or patches of Ciambel oak w ithin them.
Thus, the general heterogeneous distribution
of vegetation types in our study area ma\
explain why deer mice were consistentK
al)tmdant in all \egetation types.

The can\on mouse was captured in all can-
\'on vegetation t\'pes in each season of each
year except in fall 1995, when they were not
captured in any xegetation t\pe. The canyon
mouse is generalK associated with rock\-,
slickrock, and cliff habitats (Hoffmeister 1986,

Johnson and Armstrong 1987, Fitzgerald et al.
1994). Thus, the widespread presence of rocky
substrates within most vegetation types may
explain the presence of this species in all veg-
etation types. Johnson and Armstrong (1987)
noted that \egetation in an area ma\ ha\ e lit-
tle or no effect on local distribution of this
species, but that the species is associated with
the area's rocky substrate rather than with the
plant association.

The brush mouse was most frequentK' cap-
tured in the pinyon-juniper vegetation type in
canyons, which is consistent with previous de-
scriptions of the species' habitat (Wilson 1968,
Hoffmeister 1986, Fitzgerald et al. 1994). It was
also abundant in the riparian vegetation type
where streambeds consist of heavy brush and
rocks. The pinyon mouse was most frecjuently
captured in pinyon-juniper, once again consis-
tent \\ ith pre\ ions descriptions of the species'
habitat throughout its range (Wilson 1968,
Burt and Grossenheider 1976, Armstrong 1979,
Hoffmeister 1986, Fitzgerald et al. 1994).

We captmed the Mexican woodrat in the
pin\()n- juniper \egetation type in all seasons
sampled. In 3 of the 4 seasons sampled, it was
captured in mixed-moimtain brush and ripar-
ian \egetation, and in 2 of the 4 seasons in
mixed-conifer Our results are consistent with
literature on Mexican woodrat habitat: it is

80

Great Basix Natukai.ist

f\()lunie 58

TablIl 2. Relative abundance (no. animals [)er KM) tiap-nightsj estimates of small mammals within
vegetation t\'pes of the Manti-LaSal National Forest, Utali, during summer and fall 1994 and 1995.

.a and canvon

1994

1995

.Sununer

^all

Summer

Fall

Species

.V

•V

.V

■s

X

,s

X

•V

Mes.\s

Deer mouse

Aspen

6.3

4.33

2.7

2.81

6.5

3.47

10.6

1.42

Ponderosa pine

6.1

3.11

2.5

2.49

5.9

4.52

9.3

1.66

Grass/forh-shruh

13.7

4..30

13.0

7.06

C.'WYON.S

11.3

4.10

19.0

8.68

Deer mouse

Mixed-conifer

4.8

2.38

7.7

3.56

3.2

2.08

4.9

3.44

Finyon-juniper

5.5

1.53

1.5

1.41

3.6

2.69

5.5

3.59

Mi.xed-mountain hiush

6.2

3.20

9.7

7.73

5.5

3.56

6.8

3.16

Riparian

6.1

2.81

9.6

6.69

4.4

3.51

3.9

1.32

Canyon mouse

Mixed-conifer

1.8

2.49

1.6

2.22

1.1

2.55

0.0

Pinyon-jimiper

3.1

3.00

6.3

5.76

0.6

0.97

0.0

Mixed-mountain brush

2.5

2.89

4.2

4.16

1.7

2.94

0.0

Riparian

1.5

1.46

2.9

3.24

1.9

3.23

0.0

Biiish mouse

Mi.\ed-conifer

0.0

0.6

0.82

2.0

1.71

1.0

0.71

Finyon-juniper

0.3

0.72

2.2

1.83

4.0

3.61

3.0

2.60

Mixed-mountain brush

0.1

0.22

2.3

1.40

1.8

2..36

2.4

1.62

Riparian

0.0

0.4

0.65

4.0

0.62

3.4

0.67

Finyon mouse

Mixed-conifer

0.1

0.22

0.0

0.0

0.0

Finyon-juniper

1.3

1.94

0.9

0.43

1.2

1.35

3.0

2.41

Mixed-mountain brush

0.1

0.22

0.1

0.22

().()

0.0

Riparian

0.2

0.45

0.2

0.45

0.0

0.0

Mexican woodrat

Mixed-conifer

0.0

0.2

0.27

0.2

0.27

0.0

Finyon-juniper

0.5

1.12

1.3

0.98

0.3

0.49

0.3

()..5()

Mixed-mountain I)rusli

0.2

0.45

0.4

0.42

0.5

0.50

0.0

Riparian

().()

0.8

0.80

0.2

0.29

0.2

0.29

cluiractcri.stitalK loiiiul on rock) slopes, cliffs,
and rock outcrops (Burt and Grossenheider
1976) and is associated with pinyon-juniper
woodlands (Aniistronji; 1979, ('orncly and Baker
1986, Fit/uerald et al. 1994).

We lound that canyon and brush mice were
captured primarily within canyons, and (he
Mexican woodrat was captured only within can-
yons. As mentioned ahoxe, Mexican Spotted
Owls studied in this area were located primar-
ily (>7r)V() within canyons. Willey (unpuhlished
data) found that owls within the canyons sam-
pled were lora^in^ primarily in pinyon-jimi-
per This corresponds with woodrat disliihii-
tion and abundance in oin study.

Gur results should be uselul in the dc-\fi-
opmcnt of mana^emenl plans lor (he Mexican
Spotted Owl. Prromi/sciis si^p., the iiredomi-
nant prey species of the Mexican Spottt-d Owl

(Ward and 15lock 1995), were captuii'd in a
variety of vegetation types within cainons,
and woodrats were captured ouK in cauNons.
Thus, maintaining a mixture of vegetation t>"pes
ma\ proxide a buffer against the effects of
small mammal c>cles in an> particular xi'geta-
tion type (Ward and Block 1995). Small mam-
mal jiopulations are known to fhictuate with
seed and/or cone-crop production (McKeexcr
1961, Buchanan I't al. 1990). If" a small mam-
mal si^ecies is not an extreme habitat specialist
(as the owl s picdomiiiant piH'\ species are
not), owls ma\ temporariK be abli' to moxe
into food-abundant areas and maintain \ iable
populations. Our results also suggest that the
pin\()ii-Jimiper \cgelation t\pe is an important
component ol tlii' Mexican Spotted ( )w I s liomi'
lange during smnnuM" and fall basi'd on owl
ioiaging behav ior studies and owl diet (Willey

1998]

Sm \i 1. M \\i\i \i. llAHiivr Use

81

1992, mipuhlislicd data) and the distrihution
and ahiiiidaiR'c of kvy species. iMiture reseaieh
should ad(h-ess the eoriclation between owl
sui\i\al and reprochietiN c success and the
anioinit ol piii\ oii-juniper \ t',t:;etation t>'pe with-
in (he home rantje ol indi\ idual owl pairs.

Ac:k\()\\i.i:ix;\ii:\ts

We thank the L'.S. Forest Service and Rock\
Mountain i'orest and Range Experiment Sta-
tion loi" hnuhnii; oiu" stud\'; Tony Blen/e, Jeff
l)i\oii, Adam Onerr, SancK Lehman, John
Keane. h'hii Martin, Nicole Brown, and llillarx
Heard lor Held assistance; the Montieello
Kantier District for logistical support; and
h>si"ph CJane\, William Block, Phillip Zwank,
and an anonxnious referee for constructix c
connnents.

LlTER.\TL RE CiTED

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Bl RT, W.H., .WD R.P Crossfaheider. 1976. Peterson field
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Received 1 April IWT
Accepted 5 August 1997

Great Basin Naturalist 58(1). © 1998, pp. 82-8fi

LATE PLEISTOCENE MICROTINE RODENTS FROM
SNAKE CREEK BURIAL CAVE, WHITE PINE COUNTY, NEVADA

Christopher J. Bell''2 and Jim 1. Mcad^

Abstract. — A total of 395 microtine rodent specimens recovered from Snake Creek Burial Cave (SCBC) are
referred to Microtus sp. and Lemmiscus curtatus. Radiocarbon and Uranium series dates indicate an age for these fossils
of between 9460 ± 160 yr. B.R and 15,1000 ± 700 yr. B.P The sample of lower first molars o{ lA'tiuniscus includes 4-, 5-,
and 6-closed triangle moq5hot>pes. Earlier reports of the 4-closed triangle morphot>'pe are from Iniiigtonian deposits
in Colorado, Nevada, and New Mexico and from early Rancholaljrean deposits in \Vashington. The moiphotype is not
knowii in living populations of Lemtni.scus. SCBC specimens constitute the xoungest record of the 4-closed triangle
morphotype and are the only specimens reported from the late Rancholabrean. The time of disappearance of Lemmuscus
with this molar morphology is unknown, but populations with this morphot\pe possibly became extinct at or near the
end of the Pleistocene.

Key words: Lemmiscus, Microtus, Pleistocene, extinction.

Terrestrial vertebrate faunas of the Rancho-
labrean mammal age (late Pleistocene) from
the central Great Basin have, for the most part,
been discovered via exploration and excava-
tion of cave deposits (Grayson 1993). Many of
these localities are from relatively high eleva-
tions; fewer low-elevation sites have been dis-
covered and consequently less is known of the
Rancholabrean faunal history at lower eleva-
tions. Excavations in Snake Creek Burial Cave
(SCBC), a natural trap cave from the southern
Snake Range in White Pine County, Nevada,
resulted in the recovery of an extensive xerte-
brate faiuia consisting of over 30,000 skeletal
elements (Mead and Mead 1989). The cave is
formed in a small Devonian limestone ridge
(separated from the moimtains 1)\ a broad allu-
vial fan) at 1731 m elevation and is one of the
few lowland sites in the Great Basin that has
produced a late Pleistocene fauna.

l^reliminary sampling in 1984 from the pro-
file ol a trench excaxated b\' cavers produced a
small vertebrate assemblage indicative of late
Pleistocene age (Mead and Mead 1989). More
extensive excavations were undertaken in 1987
when 4 contiguous 1 x 1-m test pits were ex-
cavated using arbitrary lO-cm stratigraphic
levels to a depth of approximateK' 1 m below
the present surface (2 ni below an established

datum point in the cave). Fossils recovered
from the upper 25 cm (Unit I) are secondariK
deposited as a result of digging activities by
cavers. A bat guano layer (Unit II = le\el 3)
marks the beginning of imdistiubed deposits
in the sequence. The highh' fossiliferous Unit
III (encompassing levels 4-10) produced the
majority of vertebrates and is the presimied
source of materials recovered from Unit 1
backdirt. The top of Unit III is radiocarbon
dated at 9460 ± 160 yr B.P (radiocarbon years
before 1950; dated material was bat guano),
and a Uraniimi series date on an E(niu.s (horse)
phalanx from near the bottom of the exca\a-
tion gave an age of 15,100 ± 700 yv. B.P (Mead
and Mead 1989).

Preliminan' discussion of the fauna and more
extensive treatments of reptilian and numer-
ous mammalian mustelid carnixore remains
were published previously (Mead and Mead
1985, Mead et al. 1989, M(-a(l and Mead 19S9).
Man\ additional components ol the small mam-
mal launa are under stud\ now, and our pui-
pose here is to document mieiotiiic rodents
from the site.

A total of 395 spi'cimens are referred to the
2 microtine rodent genera Microtus (\ oles) and
Loitmisciis (sagebrush x'oles). both ol wliitli
lia\(" rooth'ss molars with a rchitiNcK coiiijilex

'Ofpartiiicnl of InleKrativc Biology and Miiseiiin of Veilflirali' ZodIok)', University of California, Berkeley. C.\ 94720.
^Present address: Department of Geological Sciences, University of Texas at Anstin, Austin. TX 78712.
•'Department of Geology and the Qnaternary Studies Program, Northern Arizona University. Flagstall. .\/ Hlidl I.

82

1998]

13l KlAl. C;a\ 1. MlCROTINES

83

occlusal surface. The lower 1st molar (M/1),
lower 3r(l molar (M/3), upper 3r(l molar (MS/),
and edentulous dentaries of these genera are
usualK readiK' identifiable and constitute tlu>
basis for this report.

DKSCKII'IINK ACCOIATS

.\11 speciuiens are eurated into the collec-
tions ot the l^aboraton ot Quaternarx Paleon-
tolog\', Quaternary Studies Program, Northern
Arizona University (NAUQSP). Elements
listed below are followed by the specimen
number (or range of numbers). Dental termi-
nolog)' follows Repenning (1992).

Microtu.s sp. Schrank, 1798

Material. — Left dentarx with M/1 and
M/3: 7680; left deiitary with I, M/1-2: 7702;
right dentan with 1, M/1-2: 7691; right dentan'
with I. M/2^3: 7890; isolated M/1: 7681-7690,
7692-7701, 7703-7733, 7872, 7874, 7876; iso-
lated M/3: 7877-7889. 7891-7894, 7933-7936,
7938-7939; isolated M3/: 7837-7846, 7873,
7937; left edentulous dentan : 8045-8074; right
edentulous dentar>': 8019-8044.

Diagnosis. — Primary wings on the lower
1st molar of Microtus species (in the restricted
sense of Repenning 1987, 1992) are well
de\eloped and form triangles 4 and 5; sec-
ondan' wings are usualK" present. In some
e.xtinct earl\' North American representatives
of this genus (placed in the species M. parop-
cnirius) and the e.xtant M. oeconomus, the lin-
gual primarv' wing (triangle 5) of the lower 1st
molar is generalK' open and broadK' confluent
with the anterior cap on which onl\ a single
secondan,' wing may be developed (Hibbard
1944, \bungman 1975, Hall 1981). In most
other North American species, the lingual pri-
mar\ w ing is closed, and development of sec-
ondan wings and moqoholog\' of the anterior
cap are highl\- \ariable. For this reason spe-
cific identification of isolated teeth of Microtits
species is problematic (Zakrzewski 1985).
Multivariate statistical methods were shown to
be useful in discriminating isolated molars of
several species from the southwestern United
States (Smartt 1977), but no comprehensive
stud\ of this kind that includes all North
American species has yet been published. In
the absence of such a study, reliable identifica-
tion of man\' Microtus species remains impos-

sible. Most of the lower 1st molars from SCBC
ha\e 5 closed triangles (P'ig. lA), but 4 individ-
uals have a closed labial secondar>' wing (tri-
angle 6) as well. Upper 3rd molars of most
species have an anterior loop and at least 3
alternating triangles with a posterior portion
that varies in complexity; no Microtus speci-
mens show an elongated posterior extension of
M3/ as in Lt'ininisrus. ()nl\- 3 closed dentine
fields arc present on the 3rd lower molars
referred to Microtus. Grayson (1983) noted
that the position of the mandibular foramen
can be used to differentiate edentulous den-
taries o{ Microtus and Lemmiscus. In Microtus
this foramen is on or slightly dorsal to the
ridge of bone encapsulating the posterior por-
tion of the lower incisor and is clearK \ isible
when the dentaiy is laid flat on its labial sur-
face. In Lemmiscus the foramen is situated on
the anterodorsal portion of this encapsulating
ridge and is not distinctK \ isible in a direct
lingual view.

Leuuniscus curtatus (Cope, 1868)

Material. — Left dentary with I, M/1-2:
7755; left dentaiy with I, M/1: 7794; left den-
tar\ fragment with M/1: 7828; right dentarx^
with M/1: 7741, 7749, 7802, 7830; isolated M/1:
773.5-7740, 7742-7748, 7750-7754, 7756-7793,
7795-7801, 7803-7827, 7829, 7831-7836, 7875;
isolated M/3: 7895-7932; isolated M3/: 7847-
7871; left edentulous dentan: 7940-7982; right
edentulous dentary: 7983-8018.

Diagnosis. — In living Lemmiscus curtatus
the lower 1st molar has a posterior loop and 5
closed, alternating triangles (similar to that in
Fig. IB); a 6th triangle is present and may be
broadly confluent with the anterior cap, nearly
closed (Fig. IC) or completeK' closed. Gener-
alK; only the labial secondar)' wing is well
developed, although a weak lingual secondary
wing ma\ be developed. In the earliest known
populations oi Lemmiscus, the lingual primary
wing (triangle 5) is wideK' confluent with the
anterior cap (Fig. ID; see discussion). M3/s
assigned to Lemmiscus curtatus have an ante-
rior loop, 2 alternating triangles, and an elon-
gate and uncomplicated posterior loop (Repen-
ning 1992). M/3s referred to Lemmiscus have
4 closed dentine fields. Edentulous dentaries
were identified based on the position of the
mandibular foramen (see discussion under
Microtus, above).

84

Great Basin Natuiulist

[Volume 58

A

B

D

Fi^. 1. Occlusal view of left M/1 of microtiiic rodents
from Snake Creek Burial Cave: A, Microtus sp. (NAUQSP
7683); B, t\pical Leiiiiniscas ciirfatii.s morpli from S(>'BC^
(NAUQSP 7738); C, a 'complex' morpli o\ I.cuitniscii.s nir-
tatiis (NAUQSP 7747) in which the 6th triangle is nearly
closed; D, 4-closed triangle morph oi Lcininisctis cttrtatus
(NAUQSP 7734). Scale bars = 1 mm.

Discussion

Today only 2 species of Microtus (M. inon-
taiius and M. l()n<i,ic(ni(lits) are found in die
central Great Basin, including the area aiound
SGBC (Hall 1946); 2 other species (A/, pcini-
sykainais and M. ricliard.soni) presentK inhabit
regions bordering the (wc-at Basin (Hall 1981).
Microtus is reasonably well represented in late
Pleistocene faunas of the Great Basin. .\/. iitoii-
tami.s and M. lon'^icmtdiis are usually rei^orted
as questionable identilications (see sununary

in Heaton 1985), but these reports appear to
be based largely upon modem geographic dis-
tribution of taxa. Although 3 specimens from
the Tule Springs site in southern Nevada were
identified as Microtus cf. M. californicus by
Mawby (1967), no discussion was provided to
indicate how the identification was made, and
comparisons with other Microtus species may
not ha\'e been adequate. A single specimen
from Ciystal Ball Cave was tentatively identi-
fied as M. pennsijh aniens (Heaton 1985).
Eleven M2/s (NAUQSP 8075-8085) from
SCBC show distinct development of a pos-
terolingual dentine field similar to that seen in
living M. pennsijlvanicus. Although some
authors consider this feature to be uni(|ue to
M. pennsijlvanicus, it is reported to occur at
least occasionally in several other species of
Microtus (Zakrzewski 1985) and is almost uni-
versally present in M. californicus (personal
obsei-vation). It is not known to occur in Leni-
misctis. Until a complete survey of the devel-
opment of this feature in Microtus species can
be completed, we hesitate to refer these speci-
mens to any given species, but note their pres-
ence in the fauna so that future considerations
of this problem ma\ take them into account.
Despite its contributing little else to our
knowledge o\ Microtus in the Great Basin, the
material from SCBC does provide further doc-
umentation of the presence of this genus at
lower elevations dining the Pleistocene.

Although Lcnuniscns is reported from
numerous Pleistocene and Holocene localities
outside the Great Basin (FAUNMAP Working
(iroup 1994), surprisingK few reports have
been published from within this region, where
it is widespread toda\ (Hall 1946). The earliest
known occinrence in the Great Basin is in
Irxingtonian (earl)' to middle Pleistocene)
deposits in Cathedral C]a\e, located about 40
km north of SCBC (Bell 1995). We identified
Lcininiscus molars recoxered from excaxation
backdirt in Smith Creek Cave (northern Snake
i{ange) that is presuniabK I'leistocene in age
(possibly from tlu' reddish brown silt unit; see
discussion in Me;id et al. 1982). its occurrence
in the late iMeistocene was documented at
Crystal Ball Cave in Utah (Heaton 1985) and
Owl (]ave, Ne\ada (Turmnire 1987); it also is
known from Pleistocene-HolociMie deposits in
Hock Springs Cave (JefVerson et ;il. 1994) and
from several Holocene deposits within the
C;reat Basin (lv\U N MAP Working C;roup 1994).

1998]

Bl HIAlCwi; MiCHOTINKS

85

Tabi,i% 1. Stratit;rapliic clisfnhiifioii of M/1 ol Lcintniscii.s iiioiphohpes from the 1987 excavations in SCBC". Number of
specimens of eaeli in()r|)li()t\ pi', total tiinnlier of specimens, and relati\e percent of 4-close(l triangle morpliot\pes are
proxided for each stratit;rapliic Ie\el. ()nl\' le\els e.\ea\ated in priman' deposits are inchided. 41' = 4-cl()se(l triangle
iuorphot\pe; 5T = o-closetl triangle morpli()t>pe; 6T = specimens in which a 6lli triangle is well dex-eloped hut not
completely closed.

Stratigiaphic

#4T

# 5'r

# HT

•liilal #nf

V( 4T

IcM'I

Leminmu.s

Lciiiiiiiscit.s

ljininis( ii\

S|)l(llllCllS

morjihotypes

.'3 (guano)

0

3

0

3

0

4

0

1

0

1

0

4/5

0

4

1

5

0

5

1

7

2

10

10

6

1

13

1

15

7.7

7

1

15

0

16

6.7

8

0

5

0

5

0

9

0

2

0

2

0

Most molars assigned to Loiunisciis Ifoin
SCBC are indistinguishable from those of liv-
ing L. curtatits, but 4 notable e.\ceptions
oeeur: NAUQSP 7734, 7788, 7806, and 7833
are lower 1st molars in whieh the lingual pri-
inar\" wing is wideK confluent with the ante-
rior cap (Fig. ID). This relatively primitive
morpholog}' is not known to us to occur in liv-
ing L. ciirtatns. It is the onl\' moiphology pre-
sent in the SAM Cave fauna in New Mexico,
with an estimated age of 875,000 yr. B.E
(Repenning 1992). Both 4- and 5-closed trian-
gle forms arc reported from the same strati-
graphic levels in the Pit localitx in Porcupine
Cave, Colorado (a sequence dated to between
365.000 and 478,000 >r. B.R; Wood and
Barnosk\ 1994, Barnosk\ et al. 1996), and
Cathedral Cave, Nevada, also considered to
be Ir\ingtonian in age (Bell 1995). In the Pit
localit\' the relatixe abundance of the 4-closed
triangle forms decreases in successively
\ oimger stratigraphic levels, with a concomi-
tant increase in relative abundance of 5-closed
triangle forms (Wood and Barnoskx 1994). A
similar pattern was documented at the Ken-
newick Koadcut in Washington, where both 4-
and 5-closed triangle specimens were reported
(Rensberger et al. 1984, Rensberger and
Barnoskx- 1993), with the primitixe morphol-
ogy foimd predominantly in the lower part of
the section. The age of the Kennewick fauna is
not preciscl\- known, but a full re\iew of data
pertaining to the age of the Kennewick section
was provided b\ Rensberger and Barnosk\
(1993), who concluded that the lowermost
sections probabK' do not extend back into the
Iningtonian.

A total of 57 M/ls of Loniuisciis ciirtdtus
from the 1987 excavations in SCBC can be
reliably placed in the stratigraphic se(iuence;
of these, 3 are 4-closed triangle forms and 4
are relatively complex morphotypes in which
the 6th triangle is nearly closed (Fig. IC).
Four-closed triangle specimens are evenly dis-
tril)uted in the middle of the stratigraphic se-
quence (see Table Ij but are absent from the
oldest deposits; this pattern may be a result of
low sample size for each stratigraphic level.

The taxonomic status of the 4-closed trian-
gle Lemmiscus is uncertain, and for the pres-
ent we refer these specimens to Lemmiscus
curtatus. Specimens from SCBC represent the
youngest known occurrence of this mori:)hol-
ogy and demonstrate a persistence of this form
into the late Rancholabrean. The precise time
of disappearance oi Lemmiscus with this molar
morpholog) is unknown, but its absence in the
living fauna and its presence in SCBC suggest
the possibility that populations of Lemmiscus
with this morphology went extinct at the end
of the Pleistocene, perhaps in response to cli-
matic changes occurring during the glacial-
Holoccne interglacial transition.

Acknowledgments

Financial support for the SCBC excavations
was received from the National Geographic
Society (#3627-87), Geological Society of
America (#3829-87), and Northern Arizona
Uni\ersit\' Quaternar\ Studies Program. We
appreciate the assistance of the Bureau of
Land Management and U.S. Forest Service in
obtaining excavation pemiits. We are especialK'

86

Great Basin Naturalist

[Volume 58

grateful to Emilee Mead for helping with all
aspects of the project. The illustrations were
prepared by L.A. McConnaughey, and helpful
comments on an earlier version of this report
were provided by A.D. Bamosky, H.W. Greene,
C.A. Repenning, G.E. Swartz, and J. Vindum.
Travel money in support of this project was
provided by the Department of Integrative
Biologx; University of California, Berkeley.

Literature Cited

BARNOSia, A.D., TI. Rouse, E.A. Hadlv, D.L. Wood, EL.
Keesing, and V.A. Schmidt. 1996. Comparison of
mammalian response to glacial-interglacial transi-
tions in the middle and late Pleistocene. Pages
16—33 in K.M. Stewart and K.L. Seymour, editors,
Palaeoecologv' and palaeoenvironments of late Ceno-
zoic mammals; tributes to the career of C.S. (Rufus)
Churchen University of Toronto Press, Toronto,
Ontario, Canada.

Bell, C.J. 1995. A middle Pleistocene (Irvingtonian)
microtine rodent fauna from White Pine County,
Nevada, and its implications for microtine rodent
biochronologv'. Journal of Vertebrate Paleontology 1.5
(Supplement to 3):18A.

FAUNMAP Working Gkoup. 1994. FAUNMAP: a data-
base documenting late Quaternarv- distributions of
mammal species in the United States. Illinois State
Museum Scientific Papers 25.

Grayson, D.K. 1983. The paleontology- of Gatecliff Shel-
ter: small mammals. Pages 99-126 in D.H. Thomas,
editor, The archaeology of Monitor \'alley 2. Gate-
cliff Shelter Anthropological Papers of the American
Museum of Natural Histon,' 59.

. 1993. The desert's past; a natural prehistorx' of the

Cireat Basin. Smithsonian Institution Press, Washing-
ton, DC. 356 i)p.

Hall, E.R. 1946. Mammals of Nevada. University of Cali-
fornia Press, Berkeley. 710 pp.

. 1981. The manmials of North America. John Wiley

and Sons, New York. 1181 pp.

HeatON, T.H. 1985. Quaternan paleontology and paleo-
ecology of C^nstal Ball Cave, .Millard County, Utah:
with emphasis on manunals and a description of a
new species of fossil skunk. (Ireat Basin Naturalist
45:337-390.

HibbaRD, C.W. 1944. Stratigrai)h\ and Mrtchralc paleon-
tology of Pleistocene deposits of southwestern Kansas.
Bulletin of the (Geological Society of America 55:
718-754.

Jefferson, G.T, WE. Mii.i.i;n, .\1.K. Nelson, and J.I I.
.Madsen, Jr. 1994. Catalogue of late Quaternary \cr-
tebrates from Utah. Natural IIistor\ Museinn of Los
Angeles (bounty, Technical Report 9:1-34.

Mawby, J.E. 1967. Fossil vertebrates of the Tule Sjirings
site, Nevada. Pages 107-128 in II. \l. Wortliinuton

and D. Ellis, editors. Pleistocene studies in southern
Nevada. Nevada State Museum Anthropological
Papers 13.

Mead, E.M., and J.I. Mead. 1989. Snake Creek Burial
Cave and a review of the Quaternar\- mustelids of
the Great Basin. Great Basin .Naturalist 49:14.3-154.

Mead, J.I., and E.M. .Mead. 1985. A natural trap for
Pleistocene animals in Snake Valley, eastern Nevada.
Current Research in the Pleistocene 2:10.5-106.

Mead, J. I., TH. He.\ton, and E.M. Mead. 1989. Late
Quatemaiy reptiles from hvo ca\es in the east-cen-
tral Great Basin. Journal of Heqx'tolog>' 23:186-189.

Mead, J.I., R.S. Tho.mpson, and T.R. Van Devender.
1982. Late Wisconsinan and Holocene fauna from
Smith Creek Canyon, Snake Range, Nevada. Trans-
actions of the San Diego Societv of Natural Histor\-
20:1-26.

Ren.sberger, J.M., AND A.D. Barnosky. 1993. Short-tenn
fluctuations in small mammals of the late Pleistocene
from eastern Washington. Pages 299-342 in R..\.
Martin and A.D. Barnosky, editors. Morphological
change in Quaternaiy mammals of North America.
Cambridge University Press.

Rensberger, J.M., A.D. Barnosky, .\nd E Spencer. 1984.
Geologv' and paleontologv' of a Pleistocene-to-Holo-
cene loess succession, Benton Count}-, Washington.
Eastern Washington University' Reports in Archaeol-
ogy and Histon 100-39:1-105.'

Repenning, C.A. 1987. Biochronology of the microtine
rodents of the United States. Pages 236-268 in M.O.
Woodburne, editor, Cenozoic mammals of North
America: geochronolog}' and biostratigraphy. Univer-
sity' of California Press, Berkeley.

. 1992. Allophaioinys and die age of the OK or Suite.

Krestovka Sections, Yakutia. U.S. Geological Sune\
Bulletin 2037:1-98.

Smartt, R.A. 1977. The ecology of late Pleistocene and
Recent Microtus from south-central and southwest-
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Tl'RNMiRE, K.L. 1987. .\n analysis of the manunalian fauna
from Owl Cave One and Two, Snake Range, east-
central Nevada. Unpul)lishcd thesis. University of
Maine, Orono. 282 pp.

Wood, D.L., and A.D. Barnosky. 1994. Middle Pleis-
tocene climate change in the Colorado Rocky Moun-
tains indicated by fossil manunals from Porcuiune
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Youn(;man, PM. 1975. Manunals of the Yukon Territory.
National Museiuns of Canada. Publications in Zool-
ogy 10:1-192.

Zarr'/EVVSKI, R.J. 1985. The fossil record. Pages 1-51 in
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l'ui)litation S.

Received 9 May 1997
Arrrptnl 11 Ai/^'m.v/ 1997

Cn-at Basin Naturalist 58(1), © 1998, pp. S7-S9

WESTERN TOAD, BUFO BOREAS, IN SOUTHERN UTAH:

NOTES ON A SINGLE POPULATION ALONG THE EAST FORK

OF THE SEVIER RIVER

Megan Robinson'. Michael V. Donoxaii', and Tc-rn I). Scliwancrl-
Kiij H'(»cr/.v. Hulo lioicas, popuUitiou size, potcnlidl prcij. potential prcdiitor.

Anipliibiaii species, including the Nortli
American western toad, Biifo horeas, are de-
clininu; worldwide (Blaustein and Wake 1990).
This decline ma\' he related to a nuniher ol
factors includine; human interference and hahi-
tat degradation (Blaustein and Olson 1991), in-
direct effects of "stress" leading to diseases
such as "red-leg" (Care>' 1993), mineral toxins
in water that kill tadpoles (Porter and Ilakan-
son 1976), predation on juveniles and adults
(Beiswenger 1981, Olson 1989), and padiogenic
fungal infections of eggs (Blaustein et al. 1994).
Ross et al. (1995) summarized the status of B.
horeas in Utah, mapped distributions of many
disjunct populations, and cited evidence for
possible declines in populations within the
northern part of the state. These authors stressed
that surveys need to be expanded and contin-
ued, especially in southern Utah, to clarify the
status of these toads and to identif\- factors
that might affect their populations.

Recent reports of B. boreas at 3 new^ mon-
tane localities (250()->3()3() m elevation) in south-
ern Utah noted adults, egg strings, and meta-
moiphs (Ross et al. 1995). Although no exact
date w as gi\en for the presence of adults and
egg strings, metamorphs were reportedly ob-
ser\'ed in July at 2 of the 5 ponds suneyed
earlier in the \ear. These are the onl\' reports
on the ecolog}' of B. horeas in southern Utah.
Consequently, we chose to study the natural
histoPk' of a single population of B. horeas in
this area, initially focusing on {questions con-
cerning population size and structure.

We located boreal toads at a new localit\ in
Garfield Count\', Utah, along the East Fork of
the Sevier Ri\ er, not far from a site pre\iously
reported by Ross et al. (1995). The site is in

the bottom of a long canyon with a winding,
slow-m()\ ing stream whose bed is an imper-
meable la\'er of Kaiparowits clay underlain
with Claron limestone. The riparian zone is
dominated by the introduced Kentucky' blue-
grass {Poa pratensis) and smooth brome (Bro-
tniis mennis) and native wire grass (Jtincus
halticiis). Present vegetation contrasts with the
natural cover in the early 1900s, which con-
sisted of various t>pes of willows (E. L. Boshell
personal conuiiunication). A weir on the east
slope of the canyon creates a small pond about
30 m in diameter. Native stands of Engelmann
spruce {Picea engehnannii) mixed with blue
spruce (P. pungens) and Douglas-fir (Pseiulo-
tsuga menziesii) rise abo\e the riparian zone.
Adjacent areas were clearcut in the 1930s and
later replanted with ponderosa pine {Pinus
ponderosa). Access to the site is by an unim-
pro\'ed road nmning parallel to the stream.

We \isited the study site on 23 June, 6 and
21 July, 4, 17, and 31 August, and 7 September
1996, usually from mid-morning to mid-after-
noon. As we slowK walked along the main
stream, its branches, and the moist slopes on
either side of the road, we located toads and
captured them by hand. Snout-vent length
(SV^L) in millimeters and weight (\\T) in grams
were measiued for each toad before it was
released at the exact point of capture. Wart
patterns on the head and dark blotches on the
throat and lower left leg were sketched for
each indixidual. Suspected recaptures were
later identified by comparisons with these
drawings. Using the Petersen method, we esti-
mated population size, and we tested equal
catchabilit) using a zero-tnmcated Poisson test
(Fortran programs PETERSEN and ZERO,

'Department of Biolog\', Southern Utah Universit>; Cedar Cit>-, UT 84720.
^.^uthor to whom correspondence should be addressed.

88

Great Basin Natuiullst

[\blume 58

respectiveK', in Krebs 1989). Potential pre\'
types were iclentiiied from sweeps of the \'eg-
etation using insect nets, and inferences on
feeding were obtained from palpation of toad
stomachs. Potential competitor and predator
species were noted.

Forty-si.x toads were obsened; unique cap-
tures represented 35 adult toads, 17 males and
18 females. Neither tadpoles in the stream, its
tributaries, or the small pond above the weir,
nor newK' metamorphosed toadlets or poten-
tial young-of-the-year were observed. Most
toads were recorded in June [N = 11) and July
{N = 27), with fewer observations in August
{N = 6) and September {N = 2).

Males {N = 16) were smaller than females
{N = 18) in both length and weight (ANCOVA:
mean SVL for males = 86.8 mm, range 75-98
mm; mean WT for males = 64.6 g, range
52-80 g; mean SVL for females = 96.3 mm,
range 81-111 mm; mean WT for females =
92.9 g, range 52-115 g; F = 20.87; df = 1,32;
P < .001).

We compared the 25 non-recaptured toads
obsened during the first 2 xisits with tliose 8
recaptmed and 10 non-recaptured toads ob-
served during the last 5 visits to estimate pop-
ulation size. The Petersen estimate, with re-
placement, was 53 adult toads (95% CL =
38-99). A goodness-of-fit test of observed and
expected values for the zero-truncated Poisson
test of equal catchability could not reject the
null hypothesis ix^ = 1.21; df = 3, P > 0.8).

A null hypothesis, no difference between
male {N = 4) and female (A^ = 6) growth in
mm/day, was accepted (Mann-Whitne\ test, V
= 4.0, Z = 1.7, 2-tailed P \alue = 0.09). Com-
bined recaptmes for males and females allowed
an average estimate of ().17 mni/da\' (959f ('L
= 0.09-0.25) growth in SVL during the studx
period.

We swept fi\X' 10-ni transects w ith a 40-cm-
diameter insect net in the vicinity of captured
toads. The 169 arthropods caught in these
sweeps represented 7 orders: Homoptera
(27%), Coleoptera (25%), l^iptera (18%), Orthop-
tera (17%), I lymc-noptera (8%), Ileniiptcra
(4%), and Arachnida (1%). Orthopterans (;V =
29) had much larger average body lengths (20. 1
mm, 95% CL = 18.7-21.5) than those (V =
140) of all other ta.xa (2.8 mm, 957r CL =
2.4-3.1). All toad stomachs examined 1)\ pal-
pation in July and caily Aiigiisl coiilaincd
large pre\' (>2.8 mm).

Two dead adult toads were found under a
clump of dried grass in a burrow also occupied
by 4 live juvenile northern water shrews
{SoiTX ixthistris). Although we examined the
partialK dried carcasses, we could not deter-
mine that the toads were killed by shrews,
although it is suspected that shrews were
feeding on them (Fig. 1). Numerous wander-
ing garter snakes (ThmnnopJiis dedans vagrans)
were obsei"ved in the area. All were too small
(SVL < 0.5 m) to swallow any of the toads we
measured, although the\ could definitely prey
on juveniles and tadpoles. The onl\- other am-
phibian species observed at the study site was
the leopard frog, Rana pipiens, whose num-
bers appeared fewer than B. horeas (only 6
were obsened during the study period).

A population of B. horeas in southern Utah,
studied during summer 1996, contained only
large, presumabb' old adults, with no indica-
tion of size-age structure that would suggest
juvenile recruitment. The estimated popula-
tion size of 53 adults is based on indi\ iduals
that were recaptured at random; howexer,
sample sizes were uneven for the period of
study, and this number relies on the assump-
tion that grouping data into 2 samples does
not bias the true estimate of population size.
We also assumed no recruitment from migra-
tion of adult toads into or out of the study area
because of the wideK' separated populations in
this area. Growth rates estimated Ironi a \er\
small sample of ri'cai)tin'es oxer a relati\el\
short period of time probabb' do not accu-
rateb' reflect annual growth rates. A femur
fiom 10 concentric layers of bone in each
osteon ma\ indicate an old adult toad. How-
ex'cr, sections of bone liom toads ol xarious
sizes are needed to xcrify this notion, 'loads
were not obserxt'd feeding, but tlu'ir stomachs
appeared to contain largi' insi'cls (possibK
orthopterans). Because grasshoppei's are the
largest but not most abundant potential pre\,
toads maN be sciectixc-K Iceding on tlk'ni. Dead
toads can be eaten b\ shrews, but wlu'ther
shrews kill toads is not known. Numerous
wandering garter snakes ina\ picx on tadpoles
and small toads but nw too small to swallow
adult toads in this population. There appi-ar to
be lew, ii any, competitors to B. horeas lor
food and habitat space. B. pipiens and B.
horeas occur togetliei" along the water courses,
p(iliai)s suggesting that critie.il icsources lor

1998]

Notes

89

IfTTITlTnTtriTThii

Fig. 1. Venter of a dead western toad iBufo boreas) fonnd in the hnrrow of a nortliern water shrew (Sorex ixilii.slns) in
southern Utah; note the jagged, apparently chewed edge near tlie head end of the dried carcass.

suni\;il aic citlitT (liilc'ivnt lor hotli species or,
if similar, are not limiting.

Toads appear to be clumped along water
courses or in wet seepage areas with abundant
grasses and sedges, habitat similar to those
previously described for the species in other
areas (e.g., Campbell 1970). From previous
descriptions b\' Black and Brunson (1971), the
pond abo\ e the weir at this stud\ site appears
ideal lor breeding aggregations of toads.

Acknowledgments

We thank the lollowing lor ad\ ice and tech-
nical assistance: E.L. Boshell, J.T. Boyer, T.C.
Ks(]ue, B.W. Ferguson, R.A. Fridell, D. Quin-
tana, S. Robertson, R. Rodriguez, D.A. Ross,
and P Sunniiers. D. Robinson, F Hanrion, N.P
Hanrion, M. Hanrion, and J. Barraza helped
locate toads in the field. Special thanks are
extended to the U.S. Forest Serxice, Di.xie
National Forest, for financial and logistic sup-
port.

LlTER\TLRE CiTED

Beiswf.ncer. R.E. 1981. Predation hy grey jays on aggre-
gating tadpoles of the boreal toad iBufo boreas).
Copeia 1981:274-276.

Black, J.H., AND R.B. Biu nson. 1971. Breeding l)elia\i()r
of the boreal toad, Bitfo boreas boreas (Baird and
Girard), in western Montana. Great Basin Naturalist
31:109-113.

Blalstein, A.R., .\ND D.H. Olson. 1991. Declining; am-
phibians. Science 2.53:1467.

Blm STEIN, A.R., .VND D.B. Wake. 1990. Declinuig amphil)-
ian population: a global phenomenon? Tree 5:20:3-204.

Blalsteln, A.R., P.D. Hoffman, D.G. Hokit, J.M.
Kiesecker, S.G. Walls, and J.B. Hays. 1994. UV
repair and resistance to solar UV-B in amphibian
eggs: a link to population declines? Proceedings ol
the National Acadeincy of Sciences 91:1791-1795.

Campbell, J.B. 1970. Hibernacula of a population oi' Biijo
boreas boreas in the Colorado Front Range. Her-
pctologica 26:278-282.

Cakev, C. 1993. Hypothesis concerning the causes ol tiie
disappearance of boreal toads from the mountains ol
Colorado. Conser\ati()n Biolog\ 7:355-362.

KuEBS, C.J. 1989. Ecological mcthodologx. Harper 6c
Row, Publishers, New York. 65 pp.

Olson, D.H. 1989. Predation on breeding western toads
{Bitfo boreas). Copeia 1989:391-397.

Porter, K.R., and D.E. Hak\nson. 1976. To.xicity of mine
drainage to embryonic and lanal boreal toads (Bufo-
nidae: Bufo boreas). Copeia 176:327-331.

Ross, D.A., T.C. E.syLE, R.A. Fridell and P Homncil
1995. Historical distribution, cunent status and range
extension of Bufo boreas in Utah. Ilerpetological
Review 26(4): 187-189.

Received 1 May 1997
Accepted 9 May 1997

Great Basin Naturalist 58(1), © 1998, pp. 90-91

WESTERN WOOD-PEWEES ACCEPT COWBIRD EGGS

Da\id R. CAirson', Christopher B. Goguen', and Nancy E. Mathews^

Key words: Western Wood-Peivee, Contopus sorclicliilus, brood parasitism, Brown-headed C.owhird, Molothnis ater,
accepter.

The Western Wood-Pewee {Contopus sor-
dididus) is an infrequently recorded host of
the brood parasitic Brown-headed Cowbird
(Friedmann et al. 1977, Friedmann and Kiff
1985), as are the majority of tyrannid flycatch-
ers (Petit in press). A minority of cowbird host
species, termed rejecters (Rothstein 1975),
reject cowbird eggs by ejecting them from the
nest, burying them in the nest bottom, or
deserting the parasitized nest. Hosts that do
not exhibit this response to parasitism are
called accepters. Hosts tend to either accept
or reject in a consistent manner (Rothstein
1975; but see Petit 1988, Goguen and Math-
ews 1996). A species can be assumed to be an
accepter if parasitism is noted in more than
20% of its nests (Friedmann et al. 1977). Stud-
ies may underestimate the frequency of para-
sitism of rarely used hosts, if these hosts are
rejecters, because cowbird eggs may be
ejected before being obsen^ed. The status of
these hosts can be ascertained corrcctK onK
by experimentation.

Relatively few tyrannid flycatcher species
have been tested in this regard. Eastern King-
birds {Tyrannus tyrannus) and Western King-
birds {T. verticalis) are rejecters (Rothstein
1975), while Eastern Phoebes (Sayonds phochc)
and Least Flycatchers {Eui])idonax nuniniu.s)
are accepters (Rothstein 1986, Briskie and
Sealy 1987). We report experiments that demon-
strate the Western VVood-Pcwee is an accepter
species.

The stud\ site is in piuNon pinc'-onc-sccd
juniper {Pinus edulis-Jiinipcnis inonospcnna)
woodlands in Collax Clountx', northeastern New
Mexico. Ik'tvveen 1992 and 1996 we located
and monitored nests of Western Wood-Pewee
as part of a study of the nesting (Kiiainics of

the piuN'on-juniper a\'ian community-. We ex-
perimentally parasitized 10 nests during 1995
and 1996 to determine the accepter status of
Western Wood-Pewees at this site. A single
fresh Brown-headed Cowbird egg was added
to each nest, and no host eggs were removed.
Eggs were added during daylight hours at the
following stages of the nest cycle: nest-build-
ing (3 nests), egg-laying (4 nests), or early in
incubation (3 nests). Some nests were observed
for 30 min after the egg was added to record
the adult pewee's response to the introduced
egg. We considered the egg accepted if it re-
mained in the nest, with adult pewees attend-
ing, for 4 d.

At unmanipulated Western Wood-Pewee
nests we recorded a parasitism frequenc\' of
16% (16 of 101 nests). Two nests were para-
sitized multiply, each with 2 cowbird eggs.
Cowbird eggs were accepted for at least 4 d in
13 nests, hatched in 7 nests, and fledged in 3
nests. No nest fledged both a cowbird ami a
pewee or more than a single cowbiid. At 1
nest pewees accepted a cowbird egg after an
adult had plnsicalK' attacked the female cow-
bird when it first removed a pewee egg and
when it parasitized the nest 2 min later. We
noted 2 cases of possible cowbird egg rejec-
tion, 1 involving ejection and the other deser-
tion. In the former case the cowbird egg was
laid in an empty nest and disappeared before
llu' 1st pewee egg was laid. In the latter case a
nest was deserted during incubation, following
parasitism and clutch reduction fiom 3 pewee
eggs to 1 pewee egg and 1 cowbird egg.

Pewees accepted the cowbird egg at 8 of 10
(80%) experimenlalK parasitized nests. Eggs
accepted b\ pewt'cs remained in nests be-
tween I and 19 d piior to beinir depredated

l|).parliii.iil olWIIdlir.- ICcoloKV. University orWisconsiii-M.ulivin, l(>.i() l.niilcii Drue, \I.k1im.ii. W I r,:)7(Hi.

90

1998]

Notes

91

alonu \\ itli the pcwee s cliitcli. IxMiiii; renioNed
hy a huinaii ohscn-er, or liatcliint!; (1 nest). At
the nest where the cowliird hatehed, the nest-
hng Hedged snceessfulK. The innnechate re-
sponse of a pewee returning to a freshK "para-
sitized" nest, chiring ineuhation, was noted at
1 nest. This bird perched on the nest rim.
looked l)riefly into the nest, and settled down
to incubate, showing no sign ol ha\ ing noticed
any change in its nest.

Cowbird eggs disappeared within 4 d at 2
experinicntiilK' parasitized nests. At a nest tested
near the end of nest-building, the cowbird egg
disappeared w ithin 2 d and tlie pewee's clutch
was initiated 4 tl later At another nest, tested
during egg-la\ing, we found the cowbird egg
beneadi the nest when we next visited it 4 d
later; the pewee clutch had increased from 2
to 3 eggs. A 2nd cowbird egg, added upon dis-
co\en of this ejection, was foimd imder the
nest after 3 d, while the pewee clutch re-
mained intact.

The acceptance of experimentally added
cowbird eggs at 8 of 10 nests demonstrates
that the Western Wood-Pewee, like other small
t\Tannids tested so far, is a cowbird egg accepter
(Rothstein 1975). The observed desertion of
an unmanipulated nest may have resulted
from partial clutch reduction rather than para-
sitism, and thus probably does not represent
true cowbird egg rejection. Experiments have
shown at least 2 other accepter species, East-
em Phoebe (Rothstein 1986) and Cla>'-colored
Sparrow (Spizella pallida; Hill and Seal\' 1994),
to desert nests in response to partial clutch
reduction but not parasitism per se.

The disappearance of the expenmental cow-
bird egg from a nest tested during the build-
ing stage may have simply represented a gen-
eralized response to any object found in the
nest prior to the host s egg-la\ ing rather than a
response specific to brood parasitism (Roth-
stein 1975). The Least Flycatcher, an accepter,
rejected cowbird eggs that were experimen-
talK introduced to 2 nests at the building stage,
but did so by nest desertion (Briskie and Sealy
1987). Furthermore, nest predation, or remoxal
of the egg b\' a cowbird, cannot be ruled out.

However, the experiments did elicit an in-
stance of true cowbird egg rejection. The re-
peated ejection of a cowbird egg from a nest
containing a host clutch provides circumstan-
tial e\ idence that pewees possess the behav-
ioral and physical traits required to reject.

Considering the obvious selectixe acKantage
of such l)eha\ior, it is surprising that cowbird
egg ejection is not more widespread, or even
fixed, in the pewee population.

AcKNOWLKIKi.VlliNTS

W^e wish to thank the many people who
helped with nest searching and monitoring
throughout the study. Tim DeVlarco assisted
with parasitism experiments, and Peter Ziegler
obsened the parasitic act at a pew ee nest. Tlie
NRA Whittington Center and V-7 Ranch pro-
vided access to their lands and logistical sup-
port. Funding was provided by the U.S. Fish
and \\'ildlife Service and National Biological
Ser\ice as part of the national BBIRD Pro-
gram. The Max McCraw Wildlife Foundation
contributed to the costs of publication. This
work was supported b\ the Department of
Wildlife Ecology, University of Wisconsin at
Madison.

Literature Cited

Briskie, J.V, and S.G. Sealv. 1987. Responses of Least
Flycatchers to experimental inter- and intraspecific
brood parasitism. Condor 89:899-901.

Friedmann, H., .and L.F Kike 198.5. The parasitic cow-
birds and their hosts. Proceedings of the Western
Foundation for Vertel)rate Zoologx' 2:226-^304.

Friedmann, H., L.F Kiff, and S.L Rothstein. 1977. A
further contribution to knowledge of the host rela-
tions of the parasitic cowbirds. Smithsonian Contri-
butions to Zoology- 2.35:1-7.5.

GOGLEN, C.B., AND N.E. Matiieus. 1996. Nest desertion
by Blue-gra\' Gnatcatchers in association with Brown-
headed Cowliird parasitism. Animal Behaviour 52:
613-619.

Mill, D.P, and S.G. Sealy. 1994. Desertion of nests para-
sitized by cowbirds: have Cla\-coloured Sparrows
evolved an anti-parasite defence? Animal Beha\ iour
48:106.3-1070.

Petit, L.J. 1988. Adapti\e tolerance of cowbird parasitism
by prothonotan warblers: a consequence of nest-site
limitation? Animal Behav iour 41:425—432.

. In press. Host selection by cowbirds in North

America: adaption to life histon.- traits or ecological
opportunism? /;i; T. Cook, S.K. Robinson, S.I. Roth-
stein, S.G. Sealy, and J.N.M. Smith, editors, Ecology
and management of cowbirds. University of Texas
Press, Austin, TX.

Rothstein, S.I. 1975. An experinunta! and teleonomic
investigation of a\ian brood parasitism. Condor 77:
2.50-271.

. 1986. A test of optimalit%-: egg recognition in the

Eastern Phoebe. Animal Behaviour .34:1109-1119.

Received 1 May 1997
Accepted 28 August 1997

Great Basin Naturalist 58(1), © 1998, pp. 92-95

BOOK REVIEW

Few and Far Behveen: Moments in the North
American Desert. John Martin Canipl)ell.
Museum of New Mexico Press, Santa Fe,
NM. 1997. $29.95 paperbound, $40.00
clothbound.

B\' its title and theme. Few and Far Bciwcen
could be intended as a scholarly book of sci-
ence. After all, the study of deserts is science,
and archeology and anthropology are forms of
science. Photographs, too, can introduce one
to science when presented accurately and fac-
tualK'. However, to one who has been trained
academically about the deserts of North Amer-
ica (and who has trained others), to one who
has lived in the deserts for a lifetime, the book-
presents a pictorial introduction to deserts for
someone who is not trained in science. There
is little in the book of scientific worth. Fur-
thermore, it contains too many errors to be of
much value to a scientist, but even the reader
with limited knowledge of science should be
presented with accurate information.

The book consists of the author s photo-
graphs with captions and minimal discussions.
In addition, one of the illustrations is a map of
part of western North America showing the 4
different deserts of the continent, or present-
ing the "one desert which the author repeat-
edly uses in his writing. The photographs, pri-
marily studies in blacks, grays, and white, with
a few in color, are the fundamental contril)u-
tions to the publication. The written part of the
volume is limited, from Tony Hillermans (ore-
word and (-'ampbells preface, it presents 3
sections — "Origins, "The Face ol the Desert,
and "Desert l^'ople — concluding with an
extensive though incomplete bibliography.
The Museum of New Mexico Press is com-
iiiciidcd foi (he clean copy and reproduction
ol photographs and (>ampbell is compli-
mented lor his talents as a pliotograjiher, v\v\\
those pictures not direetK ol the desert, lie is
criliei/ed lor tlie man\ eirors lound in tlie

book and for using technical information with-
out documentation.

The author has been described as an arche-
ologist, anthropologist, photographer and re-
naissance writer, and the book re\eals all of
those characteristics .

Perhaps only the author knows the mean-
ing to the title Few and Far Between. It cer-
tainly cannot refer to the animals that are dis-
cussed in the book, because animals are com-
mon in deserts. It might refer to the scarcity' of
trees or other perennial plants because many
of the photographs depict these organisms,
but it couldn't mean plants in general. Deserts
are covered with ephemerals and other forbs
when physical conditions are optimal.

The 14 color photographs are a part of the
introduction to each of the 3 sections, and the
59 black-and-white photographs each occup\'
a full page accompanied b\' descriptixt- infor-
mation on a facing page. This information is
limited to 1 or 2 paragraphs, usually less than
half a page. About hiilf of diese black-and-white
photographs are in the section entitled "The
Face of the Desert. While the book is about
the desert, not all photographs are appropriate
to the desert. Photographs not related to tlu-
desert are marginalK' appropriate or totalK
inappropriate to the book s title and main
theme.

From a scientist s perspective there are se\ -
eral objections to the book's thesis. One is the
repetitive reference to the "North .\merican
Desert' as a single geographic area. This is
noted in the subtitle to the book and is rt>peatt'd
throughout the wiiting. Thc^ "Origins section,
page 2, contains a brief description of all Earth s
deserts. The statement is made that the "North
American [desert] is fifth in size, further sug-
gesting there is a single desert. Science reeog-
ni/.es both physiographic-alK and biologiealK 4
\('r\ dillereiit geographic areas and 4 uiiiciue
deserts. AddifionalK, smaller regions such as
eastern Washington and eastern I tali are desert.

92

199"

Book Ki;\ii;\\

93

but dt'cick'dK' not a pait of tlu> spccilif (K-scit
clainu'd 1)\ (]aiiipl)(,'ll.

OiR' coiuinon ciititx is loiiiid in all (licse
(liircrciit (IcsiTts — the lack ol a(K'(|ualf water
tliroimlioiit most of the year. However, this is
oiiK 1 reason for a reuion to he desiunated as
tlestit. Othi'r plixsieal features include loca-
tion oi mountain ranges and direction ol pre-
\ailinu wintls. Some of this is explained in
Campbell s intioducton statements.

In his discussion of deserts on the diflerent
continents, Campbell almost apologeticalK in-
cludes the Arctic and Antarctic regions in his
statement that "30 percent of the earth s land
surface is coxered b\- desert.' The Arctic and
Antarctic regions are, in fact, c.xtremeK cold
deserts because water is not readiK a\ailable
to support life. II(me\er, die book is about the
deserts of North America and, while illustra-
tions of die Antarctica "desert" would be inap-
piopriate, photographs of the Arctic region of
North Amenca would have made the book more
complete. If one would read in some 19th-
centun- historical writings of North America, a
reference would be found to the "Great Ameri-
can Deseit of central North America, extend-
ing from Mexico into Canada. This extensive
geographic region, now referred to as the
grasslands biome of the continent, is no longer
described as desert. Howexer, it ma\ be con-
sidered as appropriate an example of a desert
as some of those written about and shown b\'
Campbell. This Great American Desert might
also have been included as a part of the "North
American Desert" presented b\- the author.

Another objection to Campbell's presenta-
tion in photograph and dialogue is the idea
tliat the Great Basin Desert is found north and
east of its actual pli\siographic boundaries (map
on page xii). AdniittedK, these extended regions
are desert, but the\ cannot be conectly defined
as Great Basin. E.xcluding the Arctic, the 4 pri-
mar\- deserts of North America are detailed in
this map. Campbells map shows both the Cireat
Basin Desert and the Mojave Desert incor-
rectly. The Great Basin Desert, for instance,
does not extend northward into the state of
Washington, nor eastward into central and
southein Wyoming, nor into eastern Utah, nor
into northwestern or southwestern Colorado.
It certainK does not extend into northeastern
Arizona nor into New Mexico. The Great Basin
Desert conforms to the area covered by the
Basin and Range Pro\ince and is more restricted

in geographic area. (References: Phi/siop-dphy
of Western Ihiilcd States. Nevin M. Fenneman,
McGraw-Hill Book (Company, 1931; Natural
Regions of the United States and Canada,
Charles B. Hunt, W.H. Freeman and Com-
pan>, 1974; Ex))Jori)i<i. the Great Basin, Gloria
Griffen Cline, Unixersity of Oklahoma Press,
1963; The Trees and Shrubs of the Southwest-
ern Deserts, Lyman Benson and Robert A.
Darrow, University of Arizona Press and Uni-
versity of New Mexico Press, 1954; Deserts,
James A. MacMahon, Alfred A. Knopf, 1985,
this latter being one of The Audubon Society
Nature (juides and tlie onK reference of these
5 included in ('ampbcH's bibliographx.)

Campbells map is also incorrect for the
Mojave Desert. One of the important evidences
of this desert is the Larrea I Ambrosia shrub
association which extends into southwestern
Washington Countx' of Utah, into northwestern
Mohave County of Arizona (both areas are
shown on the map incorrectly as lacing Great
Basin Desert), and along the Colorado River
farther south than shown by Campbell's map.

The book contains many errors and incon-
sistencies in writing. On page 4 the caption to
the color photograph uses the binomial of the
arrowxveed as Pulchea servicea. The correct
scientific name of this shrub is Pulchea sericea.

A statement is made on page 6 that the
desert "encompasses all of Nevada, " w hich state-
ment is in error. High mountains, certainK at
elexations immediately below timberline on the
northem slopes, are not desert, even though
they are surroinided by desert. These high
mountains are sometimes refeiTcd to as "islands
in the sk>'," but these islands are not part of
the desert. A statement is made on page 50
about "the various desert mountains, ' with a
specific reference to "elevations of from more
than nine thousand feet to more than fourteen
thousand feet above sea level." This is implied
by Campbell to be desert.

On page 16 the author states that "the rain
forests of the Northwest Coast, [are] the only
true jungles of any temperate-zone region on
earth." This is not true of all such regions on
Earth, but why is this even considered in a
discussion on deserts? On unnumbered page
45 is the sentence, "Not a single major desert
plant species of the Mexican state of Sonora,
for example, grows in the desert of Washing-
ton." With the great difference in latitudes
(Sonora 30°N, Washington 45°N), how could

94

Great Basin Natl fivlist

[Vbl

anyone knowledgeable of plants expect them
to he similar in these geographicalK separated
areas? Campbell rexerts to the 19th- and early
20th-centuiy reference to the "life zones of C.
Hart Merriam" instead of using the now scien-
tifically acceptable biomes idea.

On page 50 an incorrect statement is made
that the "sage grouse is exclusive to the Great
Basin." The known distribution of the Sage
Grouse extends into southern Canada and cen-
tral North America, far beyond the reaches of
the Great Basin. Also on page 50 is a reference
to "pronghom antelope." This mammal is admit-
tedly a pronghorn, but it is assuredly not an
antelope even though the once-popular song
refers to "where the deer and the antelope
play."

On page 52 is the statement that "the Great
Basin Desert grows relatively few plant species."
The plant species may be few in number com-
pared to a tropical rain forest, perhaps, but a
great variety of forbs and annuals are found in
all North American deserts.

Reference to the creosotebush (this should
be 2 words, not 1) occurs on pages 53 and 54,
with the statement that "each . . . parent root
may produce dozens of bushes over thousands
of square feet of desert floor." The creosote
bush does clone to produce other plants over
time and over limited areas, but over "thou-
sands of scjuare feet" is an exaggeration.

The full-color illustration on page 55 is of
the purple prickly pear {0]nintia violacca).
According to N.L. Britton and J.N. Rose {Tlw
Cactaceae, Volume I, page 144), this scientific
name is (lucstionable. These authors explain
that this plant "can never be critically identi-
fied" because it was described from drawings
brought back from the Southwest and not
from actual specimens.

It is stated on page 56 that "the Sonorau
[Desert] runs right down to the sea" and "it
has its e(jually unicjue shore fauna, including
great sea tiutlcs." How can an animal, such as
a sea tiutic, that spends its entire life in the
ocean, except lor brief inoincnts on land lor
ON'iposition, be referred to as a desert animal:'

I he photo and narrative on page .5(S and
unnumbered page 59 claim that "arroNos
result . . . Ironi the absence ol closi'-grovving
vegetation. This appears to be (jnite true about
the one jiictnrcd in New Mexico, but there are
countless examples throughout the American

Southwest where arroyos do produce diverse
species and large mmibers of plants.

The caption to the photo on unnumbered
page 61 is "storm on San Rafael Reef. This
photo shows clouds, but no storm. Similarly,
that on page 62 and unnumbered page 63 is
"cloudburst on the Red Desert without any
evidence of water.

Ground temperatures are discussed on page
64 with the note that they "have reached a
staggering 190 degrees E" In the opinion of
the writer of this review, documentation of
this temperature should be included. Another
inconsistency is found on page 72 in reference
to the photo of a playa. The statement is made
that the floor of a playa may be "as flat as a
tabletop and as solid as a rock." There is no
objection to the statement, but the plava shown
is fractured with mud cracks and is anything
but flat and certainly not solid because of
these cracks. On page 74 a statement is made
that (juagmires are "bottomless. Perhaps this
is included as a form of poetic expression, but
(juagmires are not really bottomless.

A "north countn' prickK pear" is shown and
discussed on page 90 and imnumbered page j
91. In reference to fruit size, the expression is
used that "desert prickK' pears bear fruit two I
inches long; others, as with those of this little
northernmost species, are as big as thimbles. I
Compared to 2 inches, a thimble should be *
referred to as small rather than big. Is there ['
such a thing as a 2-inch thimble':' |

Swallows' nests are shown on unnuml)ered !
page 107 with the name of the Cliff" Swallow [
gi\en as lUnindo pyrrJionota on the facing page.
\\\v genus name lor this bird is Petroclwlidon. [
not Hirundo.

A statement is made on page 112 that the
Joshua tree "nearly e.xclusixeK belongs to tlK>
\h)jave [Desert]." The map on page xii shows
the Mojaxc Desert scarceK in Arizona where
Joshua trees are eonunon and not at all in
southwestern I'tah wlu're the\ aic abnntlant.
The word "nearK probabK jnstilies these
in( Insions.

In the narrative on page 116 the first para-
graph is about the accomixuu ing pictnri' ol a
Mexican blue palm. The binomial used lor the
plant, h()W('\ci'. is a s\nou\ni and not the
accepted scientilie name. Ilie second jiara- :
graph about the (ioehimi Indians has no rec- \
oguizable reference to the picture ol the palm. ;

1997

Book i\i:\ ii:\\

95

The lotiical explanation niiiiht be that this sec-
ond paragraph intiodnees "Desert People,"
which is the last section ol the hook heuinnini;;
on the next page.

The caption to tlii' color photograph on page
120 is ahont the prickK pear cactns as a food
sonrce. The photograph, ho\\e\ei", shows a tree
cholla, not a prickly pear cactns.

The discnssion on page 121 is ahont "rahhit
dri\ es." The author then states that "fifteen or
more species of other rodents were eaten" (em-
phasis added). Hiis statement suggests that
rabbits are rodents.

According to the information on page 127,
"Chaco C>an\()n lies scjuareh in a (ireat Basin
l^esert environment." As stated pre\i()usK' in
this review. New Mexico is not in the Great
Basin, although the environment may be some-
what similar, and certainK- the area in and
around Chaco Can\on is suggestixe of desert.

The photo on unnumbered page 136, show-
ing a salmon fisher's roost in Wasco Count\;
Oregon, is interesting historically, but the
Columbia River and its tributaries are defi-
nitely not in an\ desert. Like so man\' other
references, some of which are stated in this

book review, Duchesne (bounty, Utah (refer-
ence page 144), is not even remotely near a
desert.

Despite these technical criticisms, the reader
o( Few and Far Between should be entertained
by the writing, especialK such poetic expres-
sions as "1 got to go along" (page \), "desertic
Pacific coast" (page 16), the "poisoned water to
boot" (page 20), the "honest river" and the
"exotic rivers" (page 68). On the other hand,
the reader ma\ find it monotonous with some
of the redundancies that occur

Campbell may have been more at peace
with his science readers had the draft been
more carefully critiqued and edited by a com-
petent scientist, and had the author and editors
paid more attention to detail and documenta-
tion of what supposedly is fact. Few and Far
Between is obviousK not intended for the sci-
entist, but it is a photographers contribution
showing his ability to record in that medium.

Andrew M. Barnum
Professor Emeritus
Dixie College
St. George, UT 4770

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Mack, CD., and L.D. Flake. 1980. Habitat relation-
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stock ponds. Journal of Wildlife Management
44:695-700.

Sousa, WE 1985. Disturbance and patch dynamics
on rocky intertidal shores. Pages 101-124 in
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gy of natural disturbance and patch dynamics.
Academic Press, New York.

Coulson, R.N., and J.A. Witter 1984. Forest ento-
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(ISSN 001 7-361 4)

GREAT BASIN NATURALIST Vol 58 no lJanuaryl998

CONTENTS

Articles

Taxonomy of Sphaeromeria, Artemisia, and Tanacetum (Compositae,
Anthemideae) based on randomly amplified polymorphic DNA (RAPD)

E. Durant McArthur, Renee Van Buren,

Stewart C. Sanderson, and Kimball T. Harper 1

Randomly amplified polymorphic DNA analysis (RAPD) of Artemisia subgenus

Tridentatae species and hybrids E. Durant McArthur, Joann Mudge,

Renee Van Buren, W. Ralph Andersen,
Stewart C. Sanderson, and David G. Babbel 12

Bitterbrush (Purshia tridentata Pursh) growth in relation to browsing

Carl L. Wambolt, W. Wyatt Fraas, and Michael R. Frisina 28

Identity- of Mertensia ohlongifolia (Nutt.) G. Don (Boraginaceae) and its allies in

western North America Ahmed M. Warfa 38

Astragalus (Leguminosae): nomenclatural proposals and new taxa

Stanley L. Welsh 45

Regional assessment of wadable streams in Idaho, USA

Christopher T. Robinson and G. Wayne Minshall 64

Bats of the White and Inyo Mountains of California-Nevada

Joseph M. Szewczak, Susan M. Szewczak,

Michael L. Morrison, and Linnea S. Hall 66

Habitat use by small mammals in southeastern Uttih, with reference to Mexican

Spotted Owl management Maite Sureda and Michael L. Morrison 76

Late Pleistocene microtine rodents from Snake Creek Burial Cave, White Pine

Count)', Nevada Christopher J. Bell and Jim I. Mead 82

Notes

Western toad, Biifo horeas, in southern Utah: notes on a single population along

the East Fork of the Sevier River Megan Robinson,

Michael P Donovan, and Terry D. Schwaner 87

Western Wood-Pewees accept cowbird eggs Da\ id R. Curson,

Christopher B. (loguiMi, and Nancy E. Mathews 90

Book Review

Few and lar between: moments in tlu' North American Desert Ji>liii Martin

Campbell Andrew l\. Bamuiu 92

^ ^^^^^ MCZ

^^ LIBRARY

T^ MAY 2 7 1998

IT P

HARVARD
UNIVERSITY

GREAT BASIN

NATURALIST

VOLUME 58 NO 2 — APRIL 1998

BRIGHAM YOUNG UNIVERSITY

GREAT BASIN NATURALIST

http://wA\^v.lib.])yu.edu/~nms/
FAX 801-378-3733

Editor

Richard W. Baumann

290 MLBM

PO Box 20200

Brigham Young University

Provo, UT 84602-0200

801-378-5492

E-mail: richard_bii'^im'inn@bvii.edu

Assistant Editor

Nathan M. Smith

190 MLBM

PO Box 26879

Brigham Young University

Provo, UT 84602-6879 '

801-378-6688

E-mail: nathan_smith@b\'u.edu

Associate Editors

James C. Callison, Jr.

Department of Environmental Technology

Utah Vallev State College

Orem, UT'84058

Bruce D. Eshelman

Department of Biological Sciences, Universit)' of

Wisconsin-Whitewater, Whitewater, WI 53190

Jeffrey J. Johansen

Department of Biology, John Carroll University

University Heights, OH 44118

Boris C. Ko.ndratieff

Department of Entomology, Colorado State

Universitv, Fort Collins, CO 80523

Paul C. Marsh

Center for Environmental Studies, Arizona

State University, Tempe, AZ 85287

Jerry H. Scrivner
Department of Biology'
Ricks College
Rexburg, ID 83460-1100

Stanley D. Smith
Department of Biology
University of Nevada-Las Vegas
Las Vegas, NV 89154-4004

Robert C. Whitmore

Division of Forestry, Box 6125, West Virginia

University, Morgantown, WV 26506-6125

Editorial Board. Richard A. Heckmann, Chair Zoology; Jerran T. Flinders, Botany and Range Science;
Duke S. Rogers, Zoology; Bruce A. Roundy, Botany and Range Science; Richard R. Tolman, Zoolog)'; Liirn- L.
St. Clair Botany and Range Science; H. Duane Smith, Monte L. Bean Life Science Museum. All arc at
Brigham Young University. Ex Officio Editorial Board members include Stexen L. Taylor College ot Biology
and Agriculture; and Richard W. Baumann, Editor Great Ba.sin Naturalist.

The Great Basin Naturalist, founded in 1939. is published cjuarterly by Brighaui Young Uni\ersit\.
Unpublished manuscripts that hirther oiu- biological understanding of the Creat Basin and sunouiKling areas
in western North America are accepted lor publication.

Subscriptions. Anuual subscriptions to the Great Basin Naturalist for 1998 are $25 lor iucli\ idual sub-
scribers ($30 outside the United States) and $50 for institutions. The price of single issues is $12. .\11 hack
issues are in print and available for sale. All matters pertaining to subscriptions, back issues, or other busi-
ness should be directed to the Editor Great Basin Naturalist, 290 MLBM, PO Box 20200, Brigham ^ouug
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Scholarly Exchanges. Libraries or other organizations intercsti'd in ohtaininii; tlii' Great Basin Naturalist
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Copyri^lit © 199S 1)\ liiijiliam Vouii^ L'iii\tTsit\'
OfTicial piii)Iicati()n elate: 29 April 1998

ISSN(){)17-.3(S14
4-98 750 25855

The Great Basin Naturalist

FuBLisiiKi) AT Ph()\(), Utah, by

Monte L. Bf.an Life Science Museum

Biucii AM Young University'

ISSN 0{)17-3(il4

Volume 58

30 April 1998

No. 2

(;R'at Basin Naturalist 5<S(2), © 1998, pp. 97-146

CHIRONOMIDAE (DIPTERA) OF THE COLORADO RIVER,
GRAND CANYON, ARIZONA, USA,
I: SYSTEMATICS AND ECOLOGY

James E. Sublette', Lawrence E. Stexens-, and Jo.sepli 1^ Sliannon^

AnsruAt r. — W'r clcstrihe the cliiionoiiiid midge Fauna of the Colorado Ri\er between Glen Canyon Dam and Lake
Mead, .Arizona. This di-pauperate faiuia, eonsisting of 38 species, is dominated by euryeeious Ncarctic or Holarctic ortho-
cladine t;L\a. In addition, a small .Neotropical f'aunal component is represented by Poliipcdilum ohelos Sublette & Sasa
and Rhcotantitarsiis luDnatu.s Sublette & Sasa.

The following new s\non\ms are given: Protentlu's riparuis Malloch 19L5 with Tanyjiii.s InUu.s Loew 1866 [ — Procladius
(Psilotamjpm) hclliis (Loew)]: Cricotopua ohvetu.s Boesel 198.3 with Cricotopii.s (Cricotopu.s} aninihitor ((ioetghebner) 1927:
Cricotoptis cdtini.s Sublette & Sublette 1971 with Orthocladiiis infuscatus .Malloch 191.5 [-Cricotopiis (Cricotopiis) ('/i/i/.s-
catiis (Malloch)]: CV/ro/o/x/.s sithfusciis Sublette & Sublette 1971 with OrtJwcldditi.s infti.scafiis .Malloch 191.5 [= Cricoto-
piis iCricolojjii.s) infuscatus (Malloch)]. The following new species are described: Cricotopiis (Cricotopiis) blinni Sublette.
Cricotopiis iCricotopiis) hcrnnaimi Sublette, Mctriocnemus steveiisi Sublette, and Cladotamjtursus marki Sublette. We
discuss the distribution and ecolog\' of each cliironomid species collected in this large, regulated, aridlands ri\er.

Kcij words: Chironoinidac, Colorado River, distribution, cunjccious species. Glen Canijon Dam, Grand Canyon,
midges, new species, synonymies.

Altliouuli chironomid midges are often
luiniericalK dominant aquatic macroinverte-
brates in large ri\er ecosystem.s, relatively few
ta.\onomie .studies have been conducted in the
American West. The known distributions of
chiionomids in western North America are
principally based on individual species records
in various works and on comprehensive stud-
ies l)v Sublette (1960, 1964) and Sublette and
Sublette (1979). Sublette and Sublette (1979)
report on material from headwater reaches of

the Colorado River in the upper San Juan and
Gila drainages of New Mexico. Cowle\- (1995)
examines the chironomid fauna of the upper
Rio Grande, and Ruse et al. (unpublished data)
identif\' several chironomid species in the head-
waters of the Arkansas Ri\er in Colorado; both
studies report species that also occur in the
Colorado River Wolz and Shiozawa (1995) iden-
tify chironomid genera of the upper Green
Ri\er in low-xelocity habitats at the Ouray
National Wildlife Refuge, Utah, and relate flow

'3.5.50 .\. Winslow Dr.. Tucson, .\Z 85750.

^Grdiid Canyon Monitoring and Research Center. Bo,\ 22459, FlagstaH, AZ 86002-2459.

-'Department of Biologica] Sciences, Box .5460, Northern Arizona Universitj'. Flagstaff, AZ 860n.

98

Great Basin Natur.\list

[Volume 58

velocity to assemblage structure. Spindler
(1996) reports on chirononiid distribution in
10 tributaries in Grand Gan>on. Also, Pearson
(1967) and Rader and Ward (1988) describe
the invertebrate fauna of the Green River near
Flaming Gorge Dam and in the upper Colorado
River, respectively.

Chirononiid midges are abundant in the
Colorado River in Grand Canyon (Leibfried
and Blinn 1986, Blinn et al. 1992, Stevens et al.
1997). This is the largest river in the American
Southwest, flowing 2250 km from the Rocky
Mountains to the Sea of Cortez, and it is heav-
ily regulated by numerous diversions and im-
poundments (Hirsch et al. 1990). However, no
study of chironomid taxonomy has been con-
ducted in Grand Canyon.

In this paper we describe and review the
taxonomy and ecology of chironomid species
in the Colorado River between Glen Canyon
Dam and Lake Mead, including the entire
Grand Canyon section of the river. Because
our collections are primarily from the main-
stream corridor, additional collecting in tribu-
tary streams, springs, and seeps will greatly
increase the number of species recognized in
Grand Canyon (cf Spindler 1996).

Methods and Materials

Study Area

The Colorado River flows 475 km from the
base of Glen Canyon Dam (975 m elevation)
to Lake Mead (350 m elevation) through Sono-
ran and Mojave Desert terrain, thiough lower
Glen Canyon and all of Grand Canyon (Turner
and Karpiscak 1980; Fig. 1). By convention,
locations along the Colorado River are desig-
nated in river miles from Lees Ferry. The river
passes through 13 bedrock-defined geomor-
phic reaches, and the Paria (km 1) and Little
Colorado (km 98) rivers create 3 tiubidity seg-
ments (Schmidt and Graf 1990, Stevens et al.
1997).

Field Methods

Adult and pharatc a(juatic Chironomidae
were colk'cted throughout the year in 1976-77
and 1990-91 by sweep-netting riparian vege-
tation (mostly Salix exif^ua Nutt., Tainahx raino-
sissiina Loureiro, and Baccharis spp.), while
and UV Iight-tra|)|)iiig, dip-netting, and lar\al
rearing from !)enlhic sjiof and (juantitatiN'e sam-
ples (Stevens et al. 1997).

Taxononn

Taxonomic determinations and descriptions
were made by J.E. Sublette. Specimens from
Grand Canyon which are new to science, and
which also occur in other river systems, have
been included in the type series of the new
species described here. Some adult specimens
that had been collected b\' sweep-netting may
be associated with tributaries or springs; how-
ever, many individual larvae collected from
the river were reared to emergence for identi-
fication.

Most of the moiphological teniiinolog)' used
here follows Saether (1980); however, in the
Orthocladiinae the genitalia appendages were
named by position rather than homolog)- in-
ferred by Sa^ther (1980). We term the superior
volsella the basimedian gonocoxite lobe, and
the inferior volsella is here referred to as the
basidorsal and l)asiventral gonocoxite lobes. We
followed Saether's terminology for Chironomi-
nae genitalia. The terms bacatifnnn papillae
and nasijorm tubercles for structures on the
pupal wing sheath are emplo>'ed for perlen and
nasen, respectively (Sublette and Sasa 1994).
The basal palpomere of adult chironomids is
weakly chitinized and frequently partialK' col-
lapsed; consequently, only measurements for
the apical 4 palpomeres are given. The term
temporal setae here includes both the postor-
bital and outer vertical setae. If the hontal setae
are continuous with temporals, they are also
included. The length ratio of the gonocoxite to
the gonostylus is given as Gc/Gs; gonocoxite
length is measured along the xentral midline
of the gonocoxite. In the pupa the anal lobe
ratio (ALR; Soponis 1977) is the length of the
longest anal maeroseta dixided b\' the anal
lobe length. Ventral head length of the lar\a is
measured from the medial apex of the men-
tum to the outer edge of the occipital ring.

In descriptions of new species, morphome-
tric and meristic features of the holotxpe male
are listed first, with the laugi' of xarialion lor
paratypes and the number upon which tlu' sta-
tistic is based proxided pareuthetiealK unless
the holot\pi' was unicjue. In other species de-
scriptions the range is gi\'en with the uuiuIxm-
of speeiuieus upon which the statistic is based,
listed in parentheses innnediateK' following.

The original citation is given in each species
description, along with ri'fi'riMices to subse-
(|uent studies of that sjii-cies. II a sjieeies has

1998]

(iUAM) (>A\V()\ ClllKONOMli:) T.VXONOMV

99

L<Jce Powol

GUn Canyon Dam

VT
Segment

Lake Mead

MHe 249

Km doo

Scale of Kilometers

Fig. 1. Map of the stucK area bftwceii Lake Powell and Lake Mead, Arizona, showing 13 geomorphic reaches
(Schmidt and Ciraf 1990) and 3 turhidit\ segments (Ste\ens et al. 1997): CW = clearwater segment, VT = variably turbid
segment, and UT = iisuallx turbid segment. .\lso sliown is upper Lake Mead (ULM), a usualK turbid, lacustrine segment.

been reviewed or revised, literature listed in
that stud) is not included.

Deposition of type material is indicated by
tlie following abbreviations: California Acad-
emy of Science, CAS; United States National
Mviseimi of Natural Histon, LSNM; Academ\
of Natural Sciences of Philadelphia, ANSP;
Illinois Natural Histon Survey, INHS; Ameri-
can Entomological Institute, AEI; University
of California-Ri\erside, UCR; University of
Colorado, U of C; University of Minnesota,
UMN; Brigham Young University, BYU; James
E. Sublette collection, JES; Scott J. Herrmann
collection, SJH. Non-type material collected
in (irand C>an\on, unless otherwise indicated,
is retained at Northern Arizona University.

Ecology

We re\'iew existing informatioti on the ecol-
ogy of North American Chironomidae and pro-
vide some additional data from our collections.
In those cases where a species has a Holarctic
distribution, selected reference to the European
literature is made. Two regional biotic indices
have been developed in North America, based
on water qualit>' and chironomid distribution.
The North Carolina biotic inde.x (NCBI; Lenat
1993) references HilsenhofiF's Wisconsin biotic

index (Hilsenhoff 1977, 1982, 1987, 1988);
therefore, only the NCBI is cited here. The
NCBI, based on larvae from macrobenthic
samples, lists only species groups because the
taxonomy of non-adult chironomids is less de-
finiti\ e. The NCBI is based on a range of 0-10,
with 0 being the most intolerant to pollution
and 10 the most tolerant. As Lenat (1993) indi-
cates, comparisons between diflPerent geograph-
ic regions ma> be uncertain; nevertheless, be-
cause citation of ecological tolerances from
other regions may have value for broad-ranging
species, it is provided here.

Taxonomic Descriptions

Subfamily Tanypodinae
Procladius {Psilotanypiis) hellus (Loew)

Tanypus bellus Loew 1866:4; type locality, D.C.

Protenthes riparius Malloch 1915:389; type locality,
Thompson's Lake, Havana, IL. New synnmjm.

Procladius riparius (Malloch); Roback 1971:167, holo-
t\ pe male.

Procladius hellus (Loew); Kowalyk 1985:88, lar^'aI mor-
phology.

Procladius (Psilotanijpus) hellus (Loew); Roback 1971:
162, revision, synon\my, adults; 1980:.31, lar\a and pupa;
Sublette and Sublette 1979:61, in list; Parkin and Stahl
1981:122 and Stahl 1986:70, ecology; Hudson et al. 1990:5,

100

Great Basin Natur\list

[Volume 58

in list; Oliver et al. 1990:15, in catalog; Epler 1995;3.54,
lana.

DiACXOSlS. — Adults: Keyed from other
members of the Nearctie fauna by Hoback
(1971); larva and pupa keyed by Roback (1980).
Adults range from almost black (early season
collections or at higher elevations or latitudes)
to pale yellow with pa\c orange-l)rown xittae.

Discussion. — Pwcladius ripariiis, here syn-
onymized with P. belliis, is a typical dark form
except for genitalia (Roback 1971). Examina-
tion of specimens from within the range of
Malloch's original material suggests that pinned
specimens and genitalia mounts were mixed,
with the genitalia nominally associated with
the pinned holot>'pe of P. riparius actually
being that of Coelotanypiis concinnus (Coquil-
lett). Both species occur in central U.S. and,
presumably, the specimens were inadvertently
switched when slides from the collection were
mounted. Malloch's presumptive holotype P.
riparius genitalia were illustrated by Roback
(1971: Figs. 254, 255) with a double megaseta,
a condition that has been observed frequently
in C concinnus but not in species of Procla-
dius (Psilotanypus) . Roback (1971) synonymized
the paratypes of P. riparius but not the holo-
type, because of the peculiar genitalia.

Ecology. — Typically, P. bellus occurs in the
littoral zone of lakes and reservoirs (Sublette
1957, Rosenberg et al. 1984) or other shallow
lentic water (Wrubleski 1987, Wrubleski and
Rosenberg 1990), in slow-moving streams, and
along backwater areas of faster moving streams.
It was unconnnon in a Laurentian stream sys-
tem, occurring in quiet water on finer sedi-
ments with vegetation (Cloutier and Harper
1978), and rare, comprising only 0.4% of Tany-
podinae males/m^/yr, in a brown-water stream
in Alberta (Boerger 1981). Ferrington and Crisp
(1989) reported that this species is characteris-
tic of the recovery region below enrichment
zones produced by wastewater treatment plant
effluents in 2 small streams in Kansas. In the
upper Arkansas River, Colorado, adults were
taken at 1444-1618 m elexation (liuse t>t al.
unpublished data). The single Crand ('anyon
specimen was collected near the inflow into
Lake Mead during high lake level.

DlSTIUBlTlox. — WidcK distributed in North
America.

MVIKHIAL i:.\/\V1INI:d. — AZ: Coconino Co.,
Crand Canyon National Park, C'olorado l^iver,
1 S , river mi 269.5, 365 m ele\ .

SUBFAMII.Y OlAMESINAE

Diamcsa hctcropus (Co(|uillett)

(Fifts. 2-5)

Tdnypus hctcropus Cotjuillett 1905:66; type loealities,
Wasliington, New Mexieo, and New Hampshire (Hansen
and Cook [1976] sus^est the t\pe series was mixed).

Diamesa lictcropu.s (Ccxjuillett); Hansen and (^ook
1976:9.5, revision, synonymy, distrihntion; Sublette and
Sublette 1979:64, in list; Ferrington 1983:106, distribu-
tion; Herrmann et al, 19S7:321, distribution; ()li\er et al.
1990:17, in eatalog.

Pupa. — The pupa has been known pre\i-
ously (Hansen and Cook 1976) but not de-
scribed. Exuviae entirely pale brown to dark
brown. Abdomen length 3.32-6.11 mm.

CcpJudothorax: Large frontal setae present
on the frontal apotome (Fig. 2); length 139-281
|Hm. Thoracic horn (Fig. 3), length 359-515
|im. Median suture with moderate tubercles
on either side. Precorneal setae 2, of une(]ual
length, with the longer being 139-281 |lm.
Dorsocentrals 3, small, almost in a line, with
the anterior seta being largest. Wing sheaths
without bacatiform papillae or nasiform tuber-
cles.

Abdomen: Spine pattern (Fig. 4). Anal lobe
(Fig. 5); anal macrosetae length 289-372 |im;
ALR 0.79-0.84.

Diagnosis and discussion. — The combi-
nation of hairy eyes, plumose antenna, and
distinctive genitalia (Hansen and Cook 1976:
Fig. 113) serves to differentiate the male. The
pupal armature (Fig. 4) appears distincti\e
among western Diamcsa. Tergal and sternal
spines are similar to those of Diamcsa incall-
ida (Walker) (cf Sa;ther 1969: Fig. 13, as Dia-
mcsa fonticola Siether), but that species lacks
the W'ell-de\ eloped spines on tergum II of D.
hctcropus. The Dianwsa Juu/daki Hansen pupa
(previously undescribed) has a sinu'lar arma-
ture, but the sternal spines are more slciuKi'
and arc> dark to the l)ase (best obserxcd on \
\-\ll).

Ecology. — Diamcsa hctcropus. tlic most
common species (A Dianu'sa in wi'stern North
America, inhabits cool to cold streams, includ-
ing spring runs, on eobble-graxi'l-sand bot-
toms. In the ujijier Aikansas Kixcrol (^oloriido
it has been taken honi near the licadwiiters to
Pueblo Keserxoir at i-lexations of 14.31-2905
ui (Huse et al. unpublished data). In New Me.\-
ico it is wideK distributed below elexations of
2000 m, iisualK' emerging from September
tln-ouuh March (Sublette autl Sublette 1979).

1998]

Grand Canyon (iiiiiioNoMii) Taxonomy

101

Til ^'"^-^

V

5

Tin

Sffl »^_^^<XA<'

.^t(^

X X V- -

Figs. 2-5. Diamesa heteropits. Pupa: 2, frontal apotome; 3, respiraton horn; 4. abdominal spine pattern (the T IV/S
l\"-T \'III/S VIII spine sets are showii sequentially); 5, anal lobe.

The species is rare in Grand Canyon, probably MATERIAL EXAMINED. — AZ: Coconino Co.,

due to the lack of suitable substrata through- Grand Canyon National Park, Colorado River,

out much of the canyon. 1 specimen from river mi 6T0, 840 m elev

Distribution. — Alaska to Minnesota, south Reared material from New Mexico and Col-

to California and New Mexico. orado was also examined.

102

Great Basin Naturalist

[\ blume 58

S UBFAM 1 Lv Oku iocl.\di I \ ae

Cardiocladius platypus (Coquillett)

(Figs. 6-9)

Orthocladhis platiipii'i Cociiiilk-tt 1902:93; hpe localitx.
Flagstaff, AZ.

Cardiochulhis platijpm (Coquillett); Sublette 1966:587,
review; Oliver et al. 1990:21, eatalog.

Because the original description by Coquil-
lett (1902) and redescription by Sublette (1966)
were based on an imperfect pinned holotype,
the following data are provided to augment
these descriptions.

Male. — Coloration: Almost entirely lilack-
ish brown; humeral and pleural areas very
slightK- paler

Head: Antenna with 13 flagellomeres. Anten-
nal ratio 1.51-1.63 (3). Palpal proportions 86:
156:187:250 (1) |im. Eyes reniform, with a
slightly angular medial margin. Ocidar ratio
0.56-0.60 (4). Clypeus rectangular, distinctly
\\ider than high, about as wide as the antennal
pedicel; cKp/ped ratio 0.96-1.20 (4); with 26-28
(4) setae. Temporal setae 8-12 (4), in a slightly
staggered single row, reaching to 0.68 of the
distance from the eye to midline of the head.

Thorax: Antepronotum almost parallel- sided,
not produced at the dorsal apex (Fig. 6). Tho-
racic chaetotaxy: lateral antepronotals 7-10 (4);
dorsocentrals 14-23 (5), anteriorly in a partial
double row; acrostichials 13-21 (4); prealars
5-7 (5); supra-alars lacking; scutellars 30-32
(5), in a strewn pattern.

Wing: Membrane with microtrichia visible
at 125X. Costa not produced beyond R4+5,
which ends distal to M34.4 at 0.22 of the dis-
tance between apex of M3^4 and Mj + o- f^2+3
evanescent at apex. Venarum ratio 1.02-1.09
(3). Wing length 1.90-2.58 (3) mm. Squama
with 31-52 (4) marginal setae, which are 3-4X
at base, becoming 2X, then IX near the alula.
Wing vein setae: R 9-14 (4), R, 1-4 (4), other
veins without setae.

Legs: Foretibial spur length 62-74 |am (3);
middle tibial spur lengths 52-68/24-40 |Hm
(4); hind tibial spur lengths 80-102/26-40 )ani
(4). Pulvilli absent. Leg ratios: P I 0.68-0.69
(3); P II 0.43-0.49 (4); P III 0.52-0.55 (3). P
III coml) setae 9-14 (4). P III sensilla chaetica
3-6 (2).

Genitalia (Fig. 7): Ninth tergiini with 18 (2)
setae. Gc/Gs ratio 1.80-1.81 (2).

Pupa (male). — Cephalothorax pale brown
becoming dark brown [losteiiorK with a black-

ish spot over the base of each wing sheath.
Abdomen yellowish brown becoming darker
over the bases of the posterior tergal spine
clusters; abdomen length 2.46-2.89 mm (3).

Cephalothorax: Setae absent on the frontal
apotome, similar to that illustrated by Coff-
mann et al. (1986: Fig. 9.9A). Thoracic horn
lacking. Median suture with strong tubercles
on about middle 1/3 on either side; posteriori)-
the cephalothorax becomes rugose, then at
exti'eme posterior end of the suture, fine, dark
tubercles occur (Fig. 8). Precorneal setal clus-
ter with 1 long (139 |im), 1 smaller (77 lim),
and 1 very fine seta (62 |J.m). Dorsocentrals:
Dcj coarse; Dc^ smaller than, abo\'e, and slight-
ly behind Dc^; DC3 almost in a line with Dc^
and about the same size; DC4 almost directly
above DC3 and about the same size as Dc2.
Wing sheaths without bacatiform papillae or
nasiform tubercles.

Abdo7nen: Shagreen pattern and chaetotaxy
(Fig. 9); tergum I with an anterior and poste-
rior band of spines; terga lI-\ III with bands
of spinulae and spines similar to that illus-
trated for tergum V, but virtually devoid of
shagreen between median spinulae band and
posterior band of spines; anterior to the median
band on T II-\TII, each tergum is co\ered
with weak shagreen. Anal macrosetae with the
anterior 1 well separated from the posterior 2
and either simple and spinelike or with weak
apical or subapical bifurcations (Fig. 9); length
146 )iim; length of longer posterior macroseta
149 |im; ALR 0.73-1.15; sternum \II1 (Fig. 9).

Diagnosis and discussion. — The dark col-
oration and features of the male genitalia (Fig.
7) differentiate C. platypus from other Nearctic
species o{ Cardiocladius. Cardiocladius ohscu-
rus ( Johannscn) has similar coloration and gen-
italia; however, the basidorsal gonocoxite lobe
of that species (Sublette 1967; Fig. 7) is more
rounded, costa slightK' extended, and sculelluni
pale. The pupa of Cardiocladius ohscurus has
been illustrated In' Johannscn (1937) and ('off-
man et al. (1986: iMg. 9.9A, B) as C. cf ohscu-
ripcs (johannscn) (sici = ohscurus). It dillers
from C platypus, dcscribetl licrciii, in 2 notice-
able features: the apical spini\s on liiga l-\ 111
aic longer and mori- innnerous, and shagreen
is xirtualK lacking on ti-rga ll-\ II between
median and posterior bands ol denticles, hur-
llier, IJK- L-setae of T VIII are iieaxief than in
the species illustrated In (^olfmaini c[ al. (1986).

i998j

Grand Canyon Chikonomid Taxonomy

103

*t'

- ^J

8

7

Figs. 6-8. Cardindadim platypus. M.ilc; fi, aiitepronotuni, lateral \iew; 7, genitalia. Pupa; 8, cephalofhoracic tubercles
adjacent to median suture.

Pupae of the Palearctic speeies C. fiiscus Kief-
fer and C capuciniis (Zetter.stedt) differ among
the features described and illustrated 1)\' Lang-
ton (1991).

Ecology. — Card'wcladius phitypiis is an
obligate, stenothermal rheophile that occurs
throughout much of the upper Arkansas River
in Colorado, with adults taken from 1497 to

3042 m elevation (Ruse et al. unpublished data).
It has been taken in northern New Mexico (Sub-
lette and Sublette 1979; unpublished records)
in the Canadian, Rio Grande, and San Juan
drainages. It occurs at stations with substrata
ranging from rubble-gra\ el to gravel-sand.

Distribution. — California to Colorado and
New Mexico; Quebec (Oliver et al. 1990).

104

Great Basin Natuiullst

[\ blume 58

TI

Tvm

Fi^s. 9-10. Cunliudaduis platypus. I'lipa; 9, alHlomiiial shaurccii and cliactotaxx, tt'iiia I, \', \ III, aiial lolic. .iml sk'i-
iiiiiji \l!l. Cricotopiis (Cricotopus) aiuttilfilor. Male: 10. loloralion. sciiiidiaiiiaiiiiiiatit-.

Matkhial EXA.MINKD. — AZ: Coconino Co., tional .specimens examined Ironi ("alilonna.
Grand Canyon National Park, Colorado River, Colorado, and New Mexico.
1 9, river mi ().(), 947 m elev; 1 6, river mi

72.0, 796 m elev; 1 6, river mi 108.0. (i99 m
elev; 1 (5, I Hex, river mi 151.2, 550 m ele\ ; 1
6, river mi 153.0, 549 m elev; 1 6. river mi
157.0, 555 m elev; 1 6, river mi 202.0, 457 m
elev; 1 9 Pex, river mi 205.7, 451 m elev. Addi- ii\ Hduii

('licolopit.'^ (C'ricDtopus)

(imiiilalor Goetghehner

(Fiiis. 10-12)

('riinlcpiis (iiiiiiildtor ( aictiilichiicr 1927:.52; f\pc local-

1998]

Ckam) Canyon Ciiihonomid Taxonomy

105

Figs. 11-12. Crkotopii.s (Cricotopm) anmdator. Male: 11. genitalia. Pupa: 12, thoracic 1

oracic horn \ariation.

Cricotopu.s inchti Sublette and Sublette 1971:97; t\pe
l()calit>, California; male.

Cricotopu.s (Cricotopm) irivini Sublette & Sublette
1979:70. (li.stribution, subgeneric po.sition.

Cricotopus (Cricotoptis) anmilator Goetghebuer; ilir-
venoja 1973:202, adults, imiuatures, distribution, synonymy;
Laville 1979:160 and Rossaro 19<S7:3.3.3, ecologv'; LeSage
and Harrison 1980a:73, adults, distribution, .synon\m\-;
1980b:376, ecolog> ; 1980c:2. biology- of parasites; Simp-
son et al. 1983:4, adults, immatures. in kev (after Hir-

venoja 1973); Hudson et al. 1990:9, in list; Oli\er et al.
1990:23; in catalog, synonymy; Langton 1991:219, pupa.

Cricotopus olivetws Boesel 1983:88; t>pe localit\. Ohio;
male. Xcw sipioni/ni.

The adult male and pupa differ .slightK- in
some feature.s from the description of Hir-
venoja (1973). They are redescribed here to
a.s,si.st future comparison.s.

106

Great Basin Naturalist

[Volume 58

Male. — Coloration (Fig. 10): Head, fused
thoracic vittae, preepistemum, and postnotum
blackish brown; antepronotiun and scutelluni
brown but usualK' paler than postnotum;
humeral and pleiual areas yellowish; legs dark
with paler fasciae; abdomen fasciate, with dark
browTi bands interspersed with vellowish bands;
genitalia yellowish at apex, somewhat infus-
cate basally.

Head: Antenna with 13 flagellomeres. Anten-
nal ratio 1.11-1.30 (4). Palpal proportions
55-70 (3):94-101 (3):117-133 (3):195-203 |im
(3). Eyes with dorsal extension short and
wedge-shaped. Ocular ratio 0.44-0.48 (3). Cl>'-
peus at base 0.86 of width of antennal pedicel;
with 11-12 (4) setae. Temporal setae 7-10 (4),
in a single row, reaching to near the midline of
the head.

Thoracic chaetotaxy: Lateral antepronotals
5-8 (3); dorsocentrals 14-21 (7), in a partial
double row; acrostichials 16-22 (7), mostly in
2 rows; prealars 5 (3); supra-alars lacking; scu-
tellars 7-8 (3).

Wing: Membrane with microtrichia visible
at 300X. Costa extended 54-60 |im (3) beyond
R4+5, which ends distal to M3^4 at 0.16 of the
distance between apex of M3+4 and M^^2-
R2+3 ends at 0.42-0.51 (3) of the distance
between apex of R^ and R4+5. Venarum ratio
1.09-1.14 (3). Wing length 1.80-1.97 mm (3).
Squama with 8-9 (3) marginal setae. Wing vein
setae R 6-9 (3); other veins without setae.

Legs: Foretibial spur length 44 |im (3).
Middle tibial spur lengths 22-24/18-20 |im
(3); hind tibial spur lengths 46-52/16-22 |am
(3). Apical tarsomere, claws, empodium, and
hyaline lamellae; pulvilli absent. Leg ratios: P
I 0.59-0.65 (7); P 11 0.47-0.50 (3); P III
0.56-0.59 (3). Pill scnsilla chaetica 6-7 (3).

Abdomen: Abdominal tergal setae: III, medi-
ans 5 (2), laterals 12-13 (2); IV, medians 5-7
(3), laterals 13-15 (2).

Genitalia (Fig. 11): Ninth tergum willi 6-14
(3) setae. Gc/Gs ratio 2.48-2.69 (3).

Pupa. — Exuviae pale brown on posterior
part of cephalothorax and darker brown on
terga II-VI. Abdomen length 2.20-3.04 mm.
Cephalothorax: Frontal setae absent on tlic
frontal apotome. I'horacic horn variable in
shape (Fig. 12), length 120-161 )im. Median
suture with weak rugosity anteriorly on either
side. Precorneal setae are of about e(|ual lengtli
but with 1 slightly heavier. Dorsocentrals are

small, almost in a straight line. Wing sheaths
are without bacatiform papillae or nasiform
tubercles.

Abdomen: Shagreen pattern and chaetotaxy
similar to that figured in Hirvenoja (1973: Fig.
122-12). Tergum II hooks 43-65, in 2 rows; T
II with a posterior row of fine shagreen just in
front of hook row and in some specimens also
a median band of very weak shagreen. Pedes
spurii B (PSB) present on T II and T III, the
latter being somewhat smaller and less pro-
jecting. Tergum VI with an ovA to almost round
median shagreen patch of which the L/W is
0.43-0.67. Anal macrosetae length 118-148 |im;
anal lobe length 195-234 ^im; ALR 0.61-0.63.

Diagnosis and discussion. — Abdominal
and leg color patterns and genitalia of Nearc-
tic specimens are so similar to the Palearctic
species C. (Cricotopus) anmdator that various
authors have considered the 2 populations to
be conspecific. Excellent reared material from
Grand Canyon National Park and elsewhere
clearly demonstrates some slight differences
in the pupa from that described by Hirvenoja
(1973) and Langton (1991). Most notable is the
posterior shagreen band on T II as well as the
presence of PSB on both T II and T III. The
PSB on T III is, however, smaller than that on
T II and, on some specimens, difficult to dis-
cern. A reexamination of the adults shows a
slight difference in color bands of the foretibia
as well as a genitalic difference in the basidor-
sal gonocoxite lobe, which is usualK down-
turned at the apex.

Ecology. — Cricotopus anmdator inhabits
flowing water systems ranging from spring
runs to large rivers on a \ ariety of substrata
and under wide-ranging environmental condi-
tions. Larvae usually concentrate in areas of
moderate ciuTent with continuous adult emer-
gcMice, but with spring and fall emergences
accounting lor about 909(^ of emergences at
teniperatuifs of 15-16°C. Adult males swarm
at stream banks at less than 1 m height aboxi'
clumps of grass (LeSage and llanison 1980b).
In I tab the species has been taken from Ti/pha
hitifolid L. along the margin of a stream (Rossaro
I9S7). In England it was associated with Spar-
ganiitm sp. and line sediments in the Kixci-
Pang (Ruse 1992), and MiiriophijUinn spicatiint
L. in a small stream, the i^ixer Tud (Tokeshi and
Townsend 1987). Cobo and (^.on/ales (1991)
found it in relativelv low luunbers at 2 of 5

1998J

GlLWU CaNVUN ClllHONOMlU T.WCJNOMY

107

oriiaiiicalK' polluted sites on the Ri\ei" Sar in
Spain. Schinid (1993) reported it in Austria in
relati\el\ low numbers among surface and
grax el interstitial-dwellinti Ian ae in a eoldwater,
gra\el-l)()tt()med stream. SimilarK, Kownaeki
(1982) reported it to be relatively uncommon
in a small pastureland stream in Poland. Ander-
wald et al. (1991) reported it from the Danube,
a large ri\er. In (>ennany, Kownaeki and Mar-
greiter-Kownacka (1993) lound C. unnulator in
the soft sediments of the Alz River below a
lake outflow as well as the firmer sediments of
the lower stretches of the stream. La\ille and
Lavandier (1977) found this species at higher
ele\'ations in colder water over boulder-gravel
substrata which had some moss and detritus in
the French P\renees. In the Ossau \'alle\' this
species occurred at 500-2000 m elevation at
maximum temperatures of 12-15°C (Laville
and \'in^'on 1991). In Lebanon, Mouba\ed and
Laxille (1983) reported C. armulafor from the
Beirut Hi\er at 700 m elexation, in slow to
\ er> slow summertime water flows, at a sta-
tion with mosses in the current and niacro-
ph\tes on the stream margins. Sublette and
Sublette (1979) reported this species as being
widely distributed in northern New Mexico
streams, including the San Juan River, an
upper tributan of the Colorado Ri\er. In the
upper Arkansas River of Colorado it was taken
at 1497-2743 m elevation on substrata that
varied from boulder-cobble to gravel-sand
(Ruse et al. unpublished data).

DlSTHlBlTlox. — This Holarctic species is
wideK distributed in the Xearctic region from
California to Labrador.

Matkhial k.vwiixed. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
256 S 6 (some reared), 16 9 ? (some reared),
18 PP throughout the river corridor from river
mi 0.0, 947 m ele\, to river mi 269.5, 356 m
ele\:

Cricotupus (Cricotopus) blinni
Sublette, new species

(Figs. 1.3-20, 54, 55)

HoLOTiTE MALE. — Grand Canyon National
Park, Coconino Co., AZ, Colorado River mile
144.0, 570 m elev, 25-X-90, J.S., slide no.
P0014 (CAS).

Coloration (Fig. 13): Head, thoracic \ittae,
scutellum, preepisternum, and postnotum
blackish brown; antepronotum, humeral and

pleural areas yellowish; legs dark with only
tiochanters and extreme base of all femora
paler; abdomen fasciate, with T I\' entireU'
\ cllowish and the genitalia dark.

Head (Fig. 54a): Antenna with 12 llagello-
meres. Antennal ratio 1.02 (0.96-1.16; 11). Palpal
proportions 47:86:117:148 ^im (42-55:86-90:
109-1 17:148-187 |Llm; 6). Eyes with dorsal ex-
tension short and v\edge-shaped; ocular ratio
0.43 (0.41-0.50; 6). CKpeus trapezoidal, about
as wide at base as width of antennal pedicel;
with 16 (8-16; 6) setae. Temporal setae 6 (6-8;
6), of which 2 (2-3; 6) are inner verticals near
midline of the head, clearly separated from
the 4 (4-6; 6) postoculars.

Thorax (Fig. 54a): Antepronotum almost
parallel-sided near the dorsal apex. Thoracic
chaetotaxy: lateral antepronotals 5 (5-9; 6);
dorsocentrals 17 (11-25; 6), in a partial double
row; acrostichials 18 (15-20; 6), mostK' in 2
rows; prealars 4 (3-5; 6); supra-alars lacking;
scutellars 17 (13-20; 6), in a strewn pattern.

Win^.: Membrane with microtrichia visil)le
at 300X. Costa extended 52 (13-56; 6) |im
beyond R4+5, which ends distal to M3+4 at
0.22 of the distance between apex of M3+4
and Mi+2- ^2+3 ends at 0.48 (0.51-0.59: 6) of
the distance between apex of Rj and R4+5.
Venarum ratio 1.14 (1.11-1.21; 6). Wing length
1.94 (1.54-1.97; 6) mm. Squama with 5 (2-5;
6) marginal setae. Wing vein setae: R 4 (2-4;
•5), R4+5 0 (0-1; 6); other veins without setae.

Legs: Foretibial spur length 42 (36-44; 5)
|im; middle tibial spur lengths 22/20 (24-26/
22-26; 5) |im; hind tibial spur lengths 56/24
(46-60/20-28; 5) |lm. Apex of tarsomere 5,
claws, hyaline lamellae, empodium and ungi-
tractor (Fig. 54e), pulvilli vestigial. Leg ratios:
P I 0.59 (0.58-0.62; 5); P II 0.44 (0.45-0.48; 5);
P III 0.57 (0.53-0.58; 5). P III comb setae 14
(12-17; 5). P III sensilla chaetica 6 (5-9; 5).

Abdomen: Tergal setal pattern T II-T IV
(Fig. 14); setae: III, medians 4 (4-7; 5), laterals
13 (9-13; 5); IV, medians 4 (4-6; 5), laterals 11
(7-19; 5).

Genitalia (Figs. 15, 54c): Ninth tergum with
13 (10-14; 5) setae. Gc/Gs ratio 2.0 (2.03-2.24;
5). Slide mounts of this (and other) species
show much variation in the gonost\'lus, depend-
ing on the orientation; Figures 54f-h show the
appearance of the gonostylus in various rota-
tional positions. Apex of basidorsal gonocoxite
lobe without dorsal microtrichia (Fig. 54c).

108

Ghkat Basin Naturalist

[Volume 5(S

Figs. 13-15. CricDtopus (Crkoloiiiis) hiiiiiii. Male: 13, coloration, scini(lia<:iaiiniuitic; 11, Uriia ll-l\, rliactola\\; 13,
Kcnilalia.

1998]

CiiuND Canion CJiiiu)N()Mii) Taxononh

109

16

'i ;'

19

Figs. 16-20. Cricotopus (Chcotopu.ii hlitini. Pupa: 16, thoracic horn \ariation: 17. frontal ajiotonie; 18, abdominal sha-
green and chaetotaxy. Lar\a: 19, antenna; 20, mentum.

Pi PA.— Abdomen length 2.04-2.65; 2.36
mm (6). Cephalothorax: Cephalothorax pale
hrowni. Frontal setae present on the frontal
apotome (Fig. 17); frontal setal length (S6-152
jim (2). Thoracic honi \ariation (Fig. 16), length

170-226; 189 |im (6). Median suture of cephalo-
thorax with strong rugosity on either side; lat-
eral surface of cephalothorax with weak, scale-
like tubercles. Precorneal setae subequal in
length with 1 very slightly weaker than the

110

Great Basin Naturalist

[Volume 58

other 2. Dorsocentrals small, almost in a line.
Wing sheaths without haeatiform papillae or
nasifonii tuhereles.

Abdomen: Abdominal terga 1-VI pale browni.
Shagreen pattern and ehaetotaxv' (Fig. 18);
details of shagreen on tergum 111 (Fig. 54b).
Tergum II hooks 59-84; 66 (7), in 2 rows (Fig.
54d). Pedes spurii B present on terga II and
III. Anal lobe length 198-201 ^im (4); anal
maerosetae length 130-155; 145 )lm (4). ALR
0.73-0.80; 0.77 (4).

Larva. — Ventral head length 164-187 |im
(3). Head entireK' pale exeept for darkened
oceipital ring, tips of the mandible, and men-
tum.

Antenna (Fig. 19): Blade shorter than flagel-
lum; lauterborn organs large, extending to
apex of 3rd segment; ring organ at 0.23 from
the base.

Epipharyngeal region (Fig. 55b): S I apieally
bifurcate; peeten epipharyngis of 3 unequal
blades which are apparently fused (Fig. 55b);
chaetae 5; spinulae about 3; chaetulae laterales
7, variable in size and shape; chaetulae basales
2, weakly dissected apicalK'. Ungula V-shaped
with the basal sclerite (juadrangular. Preman-
dible with 1 apical tooth and a slight subapical
shelf; brush lacking.

Maxilla (Fig. 55e): Lacinial chaetulae 5;
antaxial seta shorter than lacinial chaetulae;
paraxial seta shorter than antaxial seta; palpus
with 13 sensillar structures (Fig. 55d).

Mandible (Fig. 55a): Apical tooth shorter
than combined width of the 3 inner teeth; seta
subdentalis apieally pointed; seta interna (not
shown) with 3 main branches which are sim-
ple; outer margin moderately crenulate; mola
smooth.

Menlwn (Fig. 20j: Median tooth <2X width
of 1st laterals; 2nd lateral slightly shorter than
1st and 3rd. Anterior parapods pectinate (Fig.
55c), with claws progressively diminishing in
size posteroventrally.

Dia{;nosis and discussion. — The genitalia
and chaetotaxy resemble those o{ \\\v festivel-
/M.s-group (Ilirvenoja 1973), but members of
that gr()U|i have P II sensilla chaetica which
are lacking in this species; also the abdominal
color jiattern of this species is distinctivcK dif-
ferent. It also closely resembles C. (Cricotopus)
hernnanni Sublette, new species, in genitalic
features and abdominal chaetotaxy, but that
species has a signilicanth lower anteimal ratio
and a strikingly different color pattern. Ihc

larxa is also similar to members oi the festivel-
//<.s -group, but the central tooth of the mentum
is much narrower than in knowni members of
that group. The pupa is similar to the Palearc-
tic species C. alhiforceps Kieffer (Hirvenoja
1973: Fig. 140), but that species has pedes
spurii B only on tergum II, while this species
has both PSB II and III. Also, the thoracic
horn appears to be less spinose. The pupa is
very similar to that of C. (Cricotopus) herr-
manni Sublette; however, the length of the
thoracic horn is usually less than that of C.
hernnanni, and the anal maerosetae are shorter
than 125 |lm.

Ecology. — This species is widely distrib-
uted in the cold, swift Colorado River corri-
dor, with specimens collected from Lees Ferr\'
to mile 166.5. Adults were collected from JuK
to FebruaiA'.

Distribution. — California to Colorado and
New Mexico.

Par.\t\'PES. — AZ: 2 (5 c?, collected with the
holotype (NAU). Mohave Co., 1 6, Colorado
R, Bullhead City, 5-IX-73, M.S. Mulla (UCR).
Coconino Co., 1 L, Colorado R, Grand Can-
yon National Park, ri\er mi 0.5, 950 m ele\'; 2
6 6 , river mi 133.0, 597 m elev; 1 9, river mi
133.5, 600 m elev; 1 S, river mi 144.0, 572 m
elev; 1 S , river mi 166.5, 532 m ele\'.

CA: Riverside Co., 3 S S , Laflin Ranch, be-
tween Thermal and Mecca, 15-V-70, It. tr.
(UCR); San Bernardino Co., 7 6 6, Spring
Valley L, ll-IX-73, M.S. Mulla (UCR, JES).

CO: Lake Co., 1 c?, 4 9 9, E fork of Arkansas
R, 3042 m elev, 20-21-IX-84, S.J. Herrmann.
Pueblo Co., 69 6 6, Arkansas R, Pueblo Blvd
Br, 1431 m elev, 31-X-1-XI-84, 4-XI-84, S.J.
Herrmann; 9 6 6, 22-\'III-83, P Sanchez; 70
6 6, Stilling Basin Br, below l^ieblo Res, 1444
m elev, l()-\I-85, 15-M11-85, lS-lX-85, 17-\'II-
87, S.J. Herrmann; 6 6 6, Hobson Ranch, 1504
m elev, 19-IX-85, 17-VII-87, S.J. Herrmann.
Fremont (>o., 10 6 6, Portland Br, 1535 m ele\,
21-111-85, 19-IX-85 (SjII. |FS, UC, KU, ANSR
CAS, AEl, CNC, USNM, INHS, UMN, BYU).

NM: Santa Fe Co., 22 6 6, Rio Grande,
Otowai Br, near San lldefonso Ftii'blo, 8-I.\-
74, 5-X-74, 16-\'II-76, malaise trap, sweep net,
M. Beard (JES). Socorro Co., 1 6 , Rio Cirande,
nr San Marcial, 1 l-\41-7(i, swci'p net, M. Bi'ard.
Dona Ana ('o., 6 6 6, Rio Grande, at Te.\as state
line, 15-XI-74, M. Beard. Catron Co., 8 6 6,1
9, San JMancisco R, south of Pleasanton. nr
I'Visco Hoi Spgs, l()-\ll-74, 17-l.\-74, nialai.se

1998]

Grand Canyon (.iiikonomii) Taxonomy

111

trap, 18-24-\l-74 (reared), M. Beard (JES).
Quay Co., 4 6 6, Canadian R, at mouth of
Revelto Cr, l-X-74, M. Beard. Colfa.x Co., 3
6 6 , Canadian R, H\v>' 54, at Taxlor Spgs, 3-X-
74, sweep net, M. Beard. San Juan Co., 1 d,
San yuan R, 1 mi W San Juan Co. Hospital,
18-VII-7(i, M. Beard, J. E. Sublette (JES).

This speeies is dedieated to l^r. Dean W.
Blinn, linnioloj!;ist at Northern Arizona L ni-
\ ersity, Flagstaff, for his assistance in bringing
this project to fruition.

Cricotopiis (Cricotojnis)

glohistylus Roback

(Figs. 21-32. .56)

Cricotopus idohisUjlus l^ohack 1957:10, male and female,
f\pe l()calit\. llel)ei-Mi(lua\ bridge, Wasatch Co., Utah;
Sublette and Sublette 1979:69, in list; Oliver et al. 1990:25,
catalog.

The male has been \ er\ brieih' described
and inadequately illustrated (Roback 1957).
The following is a more complete description
of the male together \\ ith descriptions of the
pupa and lana.

Male. — Coloration (Fig. 21): Head, thoracic
\ ittae, preepistemum, and postnotum blackish
blown; antepronotum and scutelhun paler than
postnotum; humeral and pleural areas \ellow-
ish; legs dark; abdomen fasciate, with dark
brown bands interspersed with \ello\\ish bands;
genitalia dark.

Head: .\ntenna with 13 flagellomeres. Anten-
nal ratio 0.63-1.17; 0.82 (17j. Palpal propor-
tions 39-78:86-140:86-117:125-164 ^im. Eyes
with dorsal extension short, wedge-shaped.
Ocular ratio 0.44-0.53 (3). Clypeus quadran-
gular, slightly wider at base than width of
antennal pedicel; with 6-19 (15) setae. Tempo-
ral setae 10-13 (6), in a slightly staggered sin-
gle row, reaching near midline of head.

Thorax: Antepronotmn moderatcK produced
at dorsal apex (Figs. 22, 56a). Thoracic chaeto-
tax>': lateral antepronotals 8-14; 11 (5); dorso-
centrals rather coarse, 17-25 (6), in a partial
double row (Fig. 56a); acrostichials 10-18 (6),
mostK in 2 rows; prealars 3-7 (6); supra-alars
absent; scutellars 21^8 (6), in a strewn pattern.

Wing: Membrane with microtrichia \isible
at 300X. Costa extended 28-50 )im beyond
R4+5. which ends distal to M3+4 at 0.39 of the
distance between apex of M3+4 and Mi+2-
R2+3 ends at 0.34-0.45 (6) of the distance be-
tween apex of Rj and R4+5. \enarum ratio
1.0-1.05 (6). Wing length 1.47-2.23 (6) mm.

S(|uama with -1-10 (6) marginal setae. Wing vein
setae: R 6-14 (6); other veins without setae.

Legs: I'^oretibial spur length 48-71 (6) |im;
middle tibial spin- lengths 31-37/20-30 (6)
|Lim; hind tibial spur lengths 56-74/22-36 (6)
jjm. PuKilli absent. Leg ratios: P I 0.53-0.57
(6); P 11 0.37-0.44 (6); P III 0.46-0.53 (6). P
HI comb setae 7-13 (6). P HI sensilla chaetica
5-10 (6).

Abdomen: Abdominal tergal setae (Fig. 23):
T HI, medians 5-13 (6), laterals 11-22 (6); T
IV, medians 8-13 (6), laterals 12-27 (6).

Genitalia (Fig. 24): Ninth tergum with 5-16
(6) setae. Gc/Gs ratio 2.31-2.48 (6).

Pupa. — Exuviae pale brown except for
darker brown shagreen patches. Abdomen
length 2.65-3.08 mm (5j.

Cephalothorax: Frontal setae present but
frequentb lost. Tlioracic horn (Fig. 25), length
88-108 |im (5). Median suture with weak rugo-
sit}' on either side. Precorneal setae with 1 long
and 2 slightly smaller setae. Dorsal anteprono-
tal seta much longer than ventral. Dorsocen-
trals small, almost in a line. Wing sheaths with-
out bacatiform papillae or nasiform tubercles.

Abdomen: Shagreen pattern and chaetotaxy
(Figs. 26, 56b-d). Tergum II hooks 57-72 (5),
in 2 rows (Figs. 26, 56e,f); anterior to the hook
row is a weak band of fine shagreen, which is
occasionally absent. Pedes spurii B present on
tergum II, broad and poorly defined. Pedes
spurii A present on terga III-VL Anal macro-
setae length 125-127 (5) )am, heavy and only
weakly curved at the tip, occasionally bifur-
cate; ALR 0.43-0.59 (5). Tergum VIII with 5
L-setae or occasionally with 4 only (as shown
in Fig. 26).

Lar\a. — Ventral head length 257 |im. Head
pale brown with posterolateral margin dark, as
are the occipital ring and tips of the mandible
and mentum.

Antenna: With 5 segments (Fig. 27); length
99 |lm; blade shorter than the flagellum, ex-
tending to level of 3rd segment; lauterbom
organs moderatcK- large but not reaching apex
of 3rd segment; ring organ at 0.29 from base of
1st segment.

Epiphanjngeal structures (Fig. 28): S I api-
calK bihircate; pecten epipharyngis of 3 un-
equal blades; chaetae 8; spinulae 5; chaetulae
laterales 6; chaetulae basales 2, weaklv fimbri-
ate apically; ungula V-shaped with basal scle-
rite quadrangular. Premandible with 1 apical
tooth; brush lacking.

112

Great Basin Naturalist

[Volume 58

22

23

•? .0,

6
*

'» *

\\

®

;ff

® *

*,«•

-^ %p

*•■

;& ;6-!

®*

FiK-S. 21-24. i'rirolopits (Criciihiiilis) 'Johisliihis. \l.ilc: 21, coloralion. sciiiidiaiii.iimnalic-; 22, aiilipniiMilnni, l.id'ial
view; 23, ttTKa II-\' tliactotaxy; 24, ncnilalia 'Idl, (li)isal; iiinldlc inlcinal skclcloii; ritilil, 2 \ir\\s ol lioiinslv lar aprx).

1998]

Gham) (].\\i()\ GiiiHoNoMin Taxonomy

113

27

Figs. 25-28. Cricotopits iCricotopusI <il()l)istij!us. I^iipa: 25, thoracic horn \ariation; 26, alitlominal shagreen and
chactota.\\\ Larva: 27, antenna; 2S. epiplian ngcal structures.

Mdiidihlc: Apical tooth sliortcr than com-
bined w idth of 3 iinier teeth; seta subdentali.s
apicalK' notched; .seta interna not discernible;
outer margin strongl\' crenulate; niola smooth.

Mentuui (Fig. 29): One median tooth which

is <2X 1st laterals that are hirger than remain-
der, which diminish in size laterally.

Maxilla (Fig. 30): Lacinial chaetae with 6
large anterior and a1)out 4 smaller posterior
blades; palpi slightK longer than wide.

114

Great Basin Naturalist

[Volume 58

Figs. 29-32. Cricotopiis (Cricotopiis) filohistylus. Lai-va: 29, nuMituni; 3{). maxilla. Crirofopiis (('rirotnpiis^ heir
Male: 31, coloration, seiiiitliagraniniatic; 32, antcpronotum, lateral view.

Body: With abdominal hair clu.stcrs of 1-4 I:)i.\(:n()sis and discussion.— The ahdomi-

setae up to 189 |lm lont^; proccrcus dark nal chaetota.xy. ma.ssive uonostyhi.s, and hiscd

brown, aix)ut as wide as lii^h, with 1 long and basiventral and basidorsal lobes ol the u;oiio-

1 short .setae on posterior laee and fi lonu (er- eo.vile distiniiuish the male of this sin-eies horn

ininal setae; eaeh i)()sterior parapod with about all other llolaretie Cricotopiis. in llirMMioja

13 yellowish bnmn elaws. (1973) C. <ilol>i.slijlus keys to the /■;/,sr//.s-tir()iip:

1998]

Gkand Canyon Ciiihonomid Taxonomy

115

howcxcr, in that ^roup the hasicloisal aiitl
bash t'litial lohcs arc iiiorc or less separated
and no spi'cics has snch a massive gonostyhis.
The pnpa, which lacks frontal setae, a scareeK
discernible PSii on T 11, a small, \\cakl\- spin-
ose thoracic horn, shagreen patches on T
III-VI well separated, and a weak L-seta on T
Mil, does not fit an\ of Ilirxenoja's groups.
The larxa, which has a central tooth of the
mentum that is less than twice the width of
the 1st laterals, also does not fit any of llir-
\ enoja's groups.

EcoLOC.Y. — This species occurs most often
in cold streams with gra\el bottoms. In Grand
GauNon it is most common in the uppermost,
clearwater reach abo\e the Paria Ri\'er conflu-
ence.

Disi lUBLTiON. — Known from Galifornia
north to Oregon and east to Montana and New
Me.xico.

Material e.\.\mi\ed: AZ: Coconino Co.,
Grand Canxon National Park, Colorado River,
74 6 6 (some reared), 8 9? (some reared), 27
Pex, rixer mi 0.0, 947 m elev, to river mi 109.0,
710 m elev. UT: Paratype 6, Wasatch Co.,
Heber-Midwa>- Br, 26-Xi-54, Gerald D. Brooks
(ANSP). Also, specimens, including reared
material, from California, Oregon, Idaho, Mon-
tana, and New Mexico (CAS, USNM, JES).

Cricotopits (Cricotopus) herrmanm
Sublette, new species

(Figs. 33^5, 57)

HoLOTYTE MALE. — Arkansas RiAcr, Fre-
mont Co., CO, Canyon Citv, 9th street bridge,
T85S, R70W, S33, 1618 m'elev, 19-IX-85, S.J.
Herrmann (CAS).

Coloration (Fig. 31): Head, thoracic \ittae,
preepisternum, scutellum, and postnotum
blackish brown; antepronotum, humeral and
pleural areas yellowish; legs dark with paler
fasciae; abdomen fasciate, with dark brown
bands interspersed with \ellow ish bands; gen-
italia yellowish at apex, somewhat infuscate
basalK.

Head: Antenna with 13 flagellomeres. Anten-
nal ratio 0.58 (0.40-0.62: 12). Palpal propor-
tions 47 (47-62; 6):86 (78-94; 6): 109 (101-117;
6): [terminal palpomere on holotype shriveled]
(156-211; 6) |im. Eyes with dorsal extension
short and wedge-shaped. Ocular ratio 0.43
(0.40-0.46; 6). Clypeus quadrangular, slight!)
narrower at base than width of the antennal
pedicel; with 8 (7-11; 6) setae. Temporal setae

9 (6-9: 6), of Wliith 4 are inner verticals near
the midline of the head wideK separated from
the remainder

Thorax: Antepronotum almost parallel-sided
in apical half (Fig. 32). Thoracic chaetotaxy:
lateral antepronotals 6 (3-6; 6); dorsocentrals
18 (13-19; 6), in a partial double row, with the
posterior setae distinctly coarser than the
anterior; acrostichials 15 (14-21; 6), partially
in 2 rows; prealars 4 (3-5; 6); supra-alars lack-
ing; scutellars 15 (16-21; 6), irregularly biser-
ial lateralK^ becoming uniserial towards the
middle, but with a median gap.

\\7/(^': Membrane with microtrichia visible
at 3()()X. Costa extended 60 (48-70; 6) ^im be-
\()nd R44-5, which ends distal to M3+4 at 0.26
of the distance between apex of M3+4 and
^1+2- f^2+3 f'lids at 0.56 of the distance be-
tween apex of R] and R4+5. Venarum ratio 1.24
(1.14-1.20; 6). Wing length 1.68 (1.52-1.90; 6)
mm. Squama with 4 (3-5; 6) marginal setae.
Wing vein setae: R 3 (3-5; 6), other veins with-
out setae.

Legs: Foretibial spur length 44 (32-50; 6)
|im; middle tibial spur lengths 26/24 (20-28/
14-24; 5) jlm; hind tibial spur lengths 58/26
(44-60/20-30; 6) |im. Pul villus vestigial but
hyaline lamella and empodium well de\el-
oped. Leg ratios: PI 0.59 (0.58-0.64; 6); P II
0.47 (0.44-0.47; 6); P III 0.58 (0.51-0.59; 6). P
III comb setae 13 (12-16; 6), with tips of the
comb setae forming an arc. P III sensilla chaet-
ica 7 (6-10; 7).

Abdomen: Abdominal tergal setae: T 111,
medians 6 (4-8; 6), laterals 10 (8-12; 6); T IV,
medians 4 (4-7; 6), laterals 10 (5-13; 6); setal
pattern similar to C. hlinni, n. sp.

Genitalia (Figs. 33, 57a): Ninth tergum with

10 (11-22: 6) setae. Gc/Gs ratio 2.22 (2.04-2.40;
6). As in other species o( Cricotopus, the gono-
stY'lus shows considerable variation in appear-
ance due to position at the time of slide
mounting; Figures 57b-d illustrate some of
the variation observed at various angles due to
slide-mounting differences.

Pupa. — Exuviae: Almost entirely pale brown;
tergum VI still darker brow n.

Cephalothorax: Frontal setae 60-70 |-im (2).
Thoracic horn (Fig. 34), length 214-275; 252
|im (7). Median suture with moderate rugosit\'
on either side; lateral surface with weak, scale-
like tubercles. Precorneal setae, 2 large, 1
slightly smaller Dorsocentrals small, almost in

116

Great Basin Natl ramst

[Volume 58

33

!i\ //

34

FiKS. 33-36. Cricoto,,u.s iCnmlnpm) Iwmnmmi. Male; 33, ijc-nitali;.. I'uixi: 31, tlw.iacic lu.n, variation: 3rx alxi-mina
sliaKreeii and chaetotaxy. Eiikicffcrirlla ilklcijni.si.'i. .Male: 3(i. Hfiiitalia.

1998]

(iKANi) (.AWON (,'lllK()\()MID TWONOMY

ir

a straiuht row. WiiiU slieath without hacati-
forni papillae or iiasilonn tiil)(.'rclc'.s.

Abdomen: Abdonien length 2.42-2.(S9 mm
(5). Shagreen pattern and eliaetotax)' (Fig. 35).
Tergum II witli (i7-(S2; 71 (5) hooks in 2 \er\
regular rows. Pedes spurii B present on terga
11 and III, with the PSB on II large and pro-
jeeting and that on III smaller and rounded.
Width of medial shagreen band on T III less
than posterior. Medial shagreen ol T \\ LAV'
0.31-0.37 (3). Anal lobe length 195-234; 214
Um (7). Anal maerosetae length 15(S-172; 162
Liui (7). ALR ().().69-().83; 0.76 (7).

DiACNOSis AND DISCISSION. — The adult
can be elearK" differentiated from C hlinni b\
the distinctixely different eoloration (ef. Figs.
13, 31). The genitalia are \e\y similar to those
of C. hlinni as well as members of the ci/liii-
f/zY/rcus-group and festiieUits-iiroup (Ilir-
\ enoja 1973); how e\er, these 2 groups differ in
eolor. The pupa is very similar to that of C.
hlinni. but it has a slightK longer thoraeie
horn and longer anal maerosetae.

Ec()L(x;y. — This speeies has been colleeted
most frequently from eokKvater streams with
gravel-sand substrata.

DISTHIBITION. — California to Colorado and
New Me.xieo.

Paratytes and material EX.\MINED. — AZ:
Coconino Co., 1 6, Grand Can\()n National
Park, Colorado R, river mi 31.0, 876 m elev; 4
6 S , river mi 31.8, 876 m elev; 2 6 6, river mi
133.0, 597 m elev. Cochise Co., 1 6, South-
western Research Station, 1646 m elev, V Roth
(UCR).

CA: 1 c5, Davis, R.O. Schuster (UCD); 1 6,
Hopeland, E.P Van Duzee (CAS); 1 6, Oak-
land, E.S. Ro.sa (CAS); 1 d, Tule R, Spnng\ille,
W.W. Wirth (USNM); 1 6, Whitewater, A.L.
Melander (USNM). .\lameda Co., 1 6, Sunol,
W.W. Wirth (USNM). Inyo Co., 1 6, Suiprise
Canyon, R.O. Schuster (CIS). Nevada Co., 1
6, S'agehen Cr, nr Hobart Mills, C.N. Slobod-
chikoff(CAS). Riverside Co., 3 6 6, PL. Boyd
Desert Research Center, Saul I. Frommer, L.
LePre; 1 6 , Horsethief Cr, 10 mi S Palm Desert,
L. LaPre; 1 6, Desert Hot Springs (UCR); 1
6, lOOO Palms Canyon, PA. Rausch (UCR).
San Bernardino Co., 1 6, Mill Cr, Thurman
Flats, PA. Rausch (UCR). Santa Clara Co., 2
6 6, Coyote Creek, R. Whitsel (JES). Shasta
Co., 118 6 6, Fall River Mills; 1 6, Hat Creek,
Pitt R, C. Apperson (BYU, CAS, INHS, KU,
JES, UCR, USNM). Sonoma Co., 1 6, Triniti,

N.W' Frazier (CAS). Tenama Co., 2 6 6, Red
Bluff (CAS). Tulare Co., I 6, E Success Res,
r.W. Fisher (UCR).

CO: Chaffee Co., IH 6 6 , Arkansas R, Rd
301. Fisherman's Br, 2338 m elev, T15S,
R78W, S3; 40 c5c5, 6 9 9, Sand Lake Br, Sal-
ida, 2143 m elex; T50N, R9E, S31, Chalk Cr; 1
6, Hw>' 285, 2338 m elev, T15S, R77W, S14.
Fremont Co., 12 6 6 , 1 ¥ ik 6 , Arkansas R.
Howard Br, 2033 m elev; 22 6 6 , Parkdale
Siding Br, 1747 m elev, T18S, R72W, S13; 17
6 6, Hw>' 115, 9th St Br, Canyon City, 1618 m
elev, T85S, R70W, S33; 9 6 6, Texas Cr Br,
1879 m elev, T19S, R73W S7; 21 6 6 , Port-
land Br. 1535 m ele\; T19S, R68W^, S 17/20. Lake
Co., 1 6 , Arkansas R, upstream from Lake Cr
inflow, 2748 m elev, TllS, R80\V: S24. Pueblo
Co., 1 6 , Arkansas R, Hobson Ranch, 1504 m
ele\; T20S, R67W S6; 6 6 6, Stilling Basin Br,
1444 masl, T20S, R66W; S36, all (except as
indicated) collected bv S.J. Herrmann (AEI,
CAS,JES, UMN, USNM).

NM: Rio Arriba Co., 1 6, Chama R, 2 mi S
Chama, Doles and Milensky; 1 6 , Chama R be-
low El Vado Dam, Doles and Milensky (JES).

This species is dedicated to Dr. Scott J.
Herrmann, Lhii\'ersit\' of Southern Colorado,
who collected a significant part of the type
series from the Arkansas Ri\er in Colorado.

Cricotopus (Cricotopiis)
infuscatiis (Malloch)

Orthucladiu.s infiiscdliis Malloch 1915:517; l\pe local-
it} , Peoria, IL.

Cricotopius (Cric(>t()})ti.sl iiifu.scatu.s (Malloch); Suhlc-ttc
and Sublette 1979:69, distribution, synonymy; LeSage and
Harrison 1980a:81 and Fig. 10, adults, imniatures, distri-
bution; 1980b:376, ecology-; 1980c:2, biolog\' of parasites;
Oliver et al. 1990:2.3. catalog, s>nonynn'.

Cricotopua ediirus Sublette & Sublette 1971:85; type
lotalit\, RL. Boyd Desert Research Center, near Palm
Desert, Rixerside Co.. C.\. AVtf synonym.

Cricotopus subfuscus Suliiette & Sublette 1971:98;
t>pe locality. Hat Creek, Fall River Mills, Shasta Co., CA.
T^eic synonym.

Cricotopus infuscatus (Malloch); Boesel 1983;83, dis-
tribution. s\non\ni\'.

Di.\c.\osis. — The sharply defined basidor-
sal and basiventral lobes of the gonocoxite
which are about of ec^ual length, the basidorsal
lobe which bears about 6-8 main setae (Sub-
lette and Sublette 1971: Figs. 6, 35; LeSage and
Harrison 198()a: Fig. 10), and the abdominal
chaetota.x\ (Sublette and Sublette 1971: Figs.
5, 34), together with the color pattern (Sub-
lette and Sublette 1971: Figs. 1, 2), separate

118

Great Basin Naturalist

[\ blume 58

this species from other Nearctic Cricotopiis.
The larva and pupa have been characterized
by LeSage and Harrison (1980a:84); both stages
are similar to those of C. (Cricotopus) iinnulu-
tor (Goetghebuer), described above. The pupa
differs in usually lacking the apical shagreen
band on T II and having a higher number of
recurved hooks on T II (63-112). The number
of recurved hooks on T II is quite variable,
with eastern populations generally having a
higher number The lawa has a strongly cren-
ulate mandible, which is in contrast to that of
C. annulator with its virtually smooth outer
mandibular margin.

Discussion. — Additional material of C. m-
fuscatus indicates a much broader range of
color variation and chaetotaxy than was previ-
ously known, hence the synonymies given
above.

Ecology. — Lenat and Folley (1983) demon-
strated a bimodal pattern of adult emergence
for adults in the infuscatus-group. LeSage and
Harrison (1980b) reported that C. infuscatus
could tolerate pollution, 80% of the popula-
tions occurred in riffles, most emergences
were at temperatures of 16-21°C, and swarm-
ing occurred over grass clumps or the ground
at less than 1 m in height at 7-11 m from the
stream margin. Ruse et al. (unpublished data)
collected adults from the upper Arkansas River
in Colorado at elevations ranging from 1431 to
2748 m.

Distribution. — Widely dispersed through-
out lower elevations and latitudes of North
America.

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
3 6 6, river mi 61.5, 826 m elev; 1 6 , river mi
63.7, 818 m elev; 1 6, river mi 164.5, 533 m
elev; 2 6 6, river mi 166.5, 532 m elev. Other
material: Adults have been examined from
throughout most of the range of this species in
North America, including extensive reared
series from South Dakota and New Mexico.

Crico topu.s (Crico top i is)
trijascia Edwards

Cricotopus trijascia Edwards 1929:.322, itkiIc. lypc
locality, England; Boescl 1983:84, disliil)iitioii.

Cricotopus (Cricotopus) trifascia I'ldwards; I lirvciinja
1973:244, adults, pupa, larva, review, distribution; Sul)-
k'ttu and Suhlt-ttc 1979:70; synouyiuy, distribution; Lavillf
1979:160 and Wilson 19S7;.39I, irolo^^; Ix-SaKcaud Harri-
son 1980a; 102, distril)ution, syuonyiu\'; 1980l):.37(i, it()lo,u\;
1980c;2, i)ioloKy of parasitt-s; Li'u;it and Follcv 1983:1.52,
phenology, distribution; Mason and LehnikuliI 1983:196,

1985:877, distribution, phenolog)-; Simpson et al. 1983:4,
distribution, adults, pupa, lar\a, in ke\ (after Hir\enoja
1973); Hudson et al. 1990:9, in list, distribution; Oliver et id.
1990:24, distribution, synonymy; Langton 1991:208, pupa.

Diagnosis and discussion. — This is the
only Nearctic species of Cricotopus that lacks
a basidorsal gonocoxite lobe. The pupa has the
distinctive features of hea\y shagreen on terga
VII and VIII as well as 2 large and 1 small
macrosetae on the anal lobe.

Ecolo(;y. — Cricotopus trifascia is usualK'
in rapidly flowing waters ranging from 1st-
order streams to large rivers (Simpson and
Bode 1980). In small streams in England it has
been taken on gravel or Ranunculus (Pinder
1980, Pinder and Farr 1987). Mason and Lehm-
kuhl (1983) reported 3 peaks of adult emer-
gence upstream from an impoundment: spring,
midsummer, and fall. However, highest num-
bers were found 23 km downstream from the
impoundment and with a unimodal, midsum-
mer emergence about a month after the up-
stream populations. In Gennany, Kowniacki and
Margreiter-Kownacka (1993) reported C. tri-
fascia as occurring more commonly in the
lower stretches of the Alz River rather than
immediately below a lake outflow; in the Fulda,
Lehmann (1971) found this species rather wide-
ly distributed, occurring in the metarhithral to
the potomal regions in moderately strong cur-
rent. The species was the dominant form in a
small, heavib' polluted stream in southern
Ontario, absent from another polluted stream,
but clearly rheophilous with at least 80% of the
populations in riffles of cobble and pebbles
densely covered b\' diatoms and filamentous
algae; adult emergences occinred at water tem-
peratures of 16-21°C, with adult male swarms
2-3 m aboveground where tree branches were
used as lateral swarm markers (LeSage and
Harrison 1980b). In an organiealK' enriched
small chalk stream in southern England this
species occurred in low numbers onl\ al an
unpolluted station (Pinder and I'arr 1987). The
larval tubes of ('. Iritdscia arc constructed
largely of detritus and lilanienlous algae or fil-
amentous algae alone, and the stream in w Inch
stones occurred had a thin aulwuchs film ex-
cept (luring sununer, at which time large areas
of stones had a (^ladophora blanket (Breiman
and McLachlan 1979). The species has been
reported from periphyton in a large stream,
the Dainibe, associated piimaiiK with Clado-
pliora (Jankovic 1973). It has been taki'ii in

1998]

Grand Canyon Ciiihonomid Taxonomy

119

low niinil)ers from 2 oi 5 stations reccixine;
orpinic cnricliincnt in the Hixcr Sar in Spain
(Cobo and Gonzales 1991). In Lebanon, C tri-
fascia occurred at 800-1200 ni at several dii-
terent stream sites, most of which had mosses
or inaeroplntes; 1 station was polluted (Mou-
l)a\ed and Laxille 1983). A population in a
3rd-order trout stream consisted of 2 cohorts
that made up 9.7% of total secondan' produc-
tion of midges (Berg and llellenthal 1992a,
1992b). The species, collected at a station with
ini'diuni le\els of zinc, was considered to be
tolerant according to tlie pollution tolerance
codes developed b\- Wilson and McCMll (1982)
(Armitage and Blackburn 1985). In New Mex-
ico, C. trifascia was an imcommon species,
occurring in the San Juan River, an upper trib-
utan of the Colorado River, and in the upper
Rio Grande (Sublette and Sublette 1979). Adults
ha\ e been taken from the upper Arkansas Ri\ er
in Colorado at elevations ranging from 1431 to
2748 m elevation (Ruse et al. unpublished data).

Distribution. — Saskatchewan to Ontario
and New York, south to California, New Mex-
ico, and North Carolina.

Material examined. — AZ: Coconino Co.,
Grand Canvon National Park, Colorado River,
2 6P, I L,' river mi 0.0, 947 m elev; 2 6 6,
river mi 53.0, 847 m elev; 3 6 6, river mi 61.5,
826 m elev; 1 c?I^ river mi 74.3, 792 m elev; 1
6 , river mi 98.0, 732 m elev; 1 Pex, river mi
151.2, 556 m elev. Other material: Specimens
ha\e been examined fiom throughout the range
of this species, including extensive reared mate-
rial from New Mexico.

Eudactylucladiu.s diibitatiis
( Johannsen)

Orthocladius (Dactylocladiiis) iliil>itiilits Joliannsen
1942:72; t>pe Iocalit>-, NY'.

Hijdrohacmt.s didntatus (Johannsen); Rohack 1957:76,
ininiaturt' stages.

Orthocladitis i Eiidactijlocladius) duhitatus Johannsen;
Sublette 1967;.5()7, re\ie\v; Hudson et al. 1990:11, in list,
distribution; Oliver et al. 1990:31, in catalog.

Eiidactylocladiu.s duhitatus (Johannsen); Sublette and
Sublette 1979:73, generic position, distribution.

Diagnosis and discussion. — The males of
this genus can be separated from the closely
related Orthocladius (s.s.) by the greatly re-
duced basidorsal and basiventral gonocoxite
lobes. The pupa has distinctive paired spinu-
lae patches on terga II or III-\T, lacks re-
cuned hooks on tergum II, and has a short,
smooth, saclike thoracic hoiTi that arises from

a short stalk. The male of E. duhitatus can be
separated from other Holarctic species by its
short anal point, basimedian gonocoxite lobes
that are not produced, and an apically tapered
gonostylus with a scarcely discernible dorso-
distal carina (cf Sublette 1967:505, Fig. 17).
The pupa has been redescribed b>' Roback
(1957:81: Figs. 194-196). Our material suggests
that this species is more variable in the pupal
stage than heretofore known: the weak, paired
shagreen patches of tergum II may be reduced
to just a few points, or even completely absent;
the apical spinulae row on tergum VIII, in like
manner, may be well developed, reduced to a
few points, or even absent. A unique feature
appears to be the presence of well-developed
pedes spurii B on terga I, II, and III.

Ecology. — Eudactylocladius duhitatus is
probabK' madicolous since the pupae are some-
times taken in streams. The madicolous biotope
occurs as a thin film of water on any solid sub-
stratum such as seeps on vertical rock faces,
splash zones of rapids and waterfalls, water
interface of emergent vegetation, and at stream
margins. Spring runs provide a stable environ-
ment and will usually include members of this
assemblage. The species, while rare in this sys-
tem, has been collected on the upper Arkansas
River of Colorado at elevations ranging from
1444 to 2143 m (Ruse et al. unpublished data).
Species of this genus occur in lakes, tempo-
rar\' ponds, swamps, and in madicolous assem-
blages on rock faces and in moist soil (Cran-
ston et al. 1989).

Distribution. — California to New Mexico
east to New York and Pennsylvania.

Material e.xamined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
2 Pex, river mi 124.6L, 625 m elev, 26-XI-91.
Other material examined: reared specimens
from California, Colorado, and New Mexico.

EukieffericUa chiripennis
(Lundbeck)

Chinmoinu.^ chiripennis Lundbeck 1898:281; t>pe local-
ity; Greenland.

EukiejfericUa clariiH'nnis (Lundbeck); Oliver 1970:
102, lectot\pe; Lehniann 1972:3.59, adult, pupa, distribu-
tion, s>noii\niy; Pinder 1974:198, Lavillc 1979:160, Wilson
1987:.391 and 1989:373, ecolog\-; Hal\orsen 1981;.34, review,
female; Hudson et al. 1990:9, bli\er et al. 1990:26, catalog,
distribution, synonymy; Langton 1991:125. pupa.

Diagnosis and discussion. — The adult male
is characterized by having bare eyes, an absence

120

Great Basin Naturalist

[Volume 58

of R.:)^3, a moderately extended costa that ends
slightly proximal to apex of M3+4 (Lehmanii
1972: Fig.7), and, al)o\e all, the features of the
male genitalia (Lehmann 1972: Fig. 6). The pupa
has a distineti\e thoraeie horn and abdominal
chaetotiL\\ (Lehmann 1972: Figs. (S, 9). The adult
is very similar to E. hrcvinercis (Malloeh) (Sub-
lette 1970:71) but differs in having a lower an-
tennal ratio (0.75-1.30; E. brevinervis, 2.0-2.4).
EcoLOCA. — Eiikiefferiella claripennis is wide-
ly distributed in lower and medium ele\ ation
streams. It is eurythermous and rheobiontie
(Lehmann 1972). Finder (1980), Finder and
Farr (1987), and Finder et al. (1987) eolleeted
it most often on Raniincuhis and gravel sub-
strates, while Ringe (1974), Halvorsen (1981),
and Nolte (1991) reported it as an inhabitant
of acjuatie mosses. Halvorsen (1981) also found
it on the surfaee of roeks in swiftly flowing
water at 500 m elevation, and Millet et al.
(1987) reported it from rocks with Cladophoro.
E. claripennis tolerates low to medium levels
of zinc and is considered to be relatixely toler-
ant according to the pollution codes of Wilson
and McGill (1982) (Armitage and Blackburn
1985). Cower et al. (1994) reported this to be
one of the most abundant and tolerant chi-
ronomids, occurring at stream stations with
high levels of copper and aluminum. Finder
and Farr (1987) collected it from stations with
elevated levels of organic enrichment in a
small chalk stream in southern England, but
not in numbers greater than at clean water sta-
tions. It has been taken from a calcareous
stream with elevated levels of zinc but not
from acid streams with higher levels of zinc
(Wilson 1988), and is considered to be a mod-
erately pollution-tolerant species (Bazerque et
al. 1989). In Lebanon, Moubayed and Laville
(1983) reported this species from a seasonal
limnocrene in eddies at the outflow, with vvatei-
temperatures ranging from 14° to 16°C; eleva-
tion was 850 m. Oliver and Sinclair (1989) re-
garded it as a member of the madicolous assem-
blage. According to Bode (1983), the chnipcn-
nis-group is the most tolerant member of the
genus, occurring from high-altitude streams (o
larger, warmer rivers. In the brown-walei
stream system studied by Boerger (1981) in
Alberta, E. claripennis constituted onl\ ().59r of
the Orthocladiinae males/m^/yr it is one of
the predominanf chirononiids thai emerged in
the spring from the Kixcr l^iiig in F^ngland
(Kuse 1992). Hinge (1974) obscncd 4 m\\\\[

emergence periods from a small stream in
central German), with most indi\iduals emerg-
ing dining the interval from June to August.
In Austria, Schmid (1993) found low lar\al
densities of this midge from a coldwater, gravel-
bottomed stream. In German) it has been re-
ported from the Danube, a large ri\'er (Andei-
wald et al. 1991), as well as a regulated, pri-
mary tributary, the lower Inn River (Reiss and
Kohmaim 1982); in the Alz River this species
avoids the soft sediments innnediatel) below a
lake outflow but is common farther downstream
(Kownacki and Margreiter-Kownacka 1993). In
the French Fyrenees the streams of the Ossau
Valley support moderate nimibers of E. clari-
pennis at elevations fi-om 500 to 800 m, in slow -
to fast-moving water; maximum temperatures
range from 15° to 18°C (Laville and Vinson
1991). Ruse et al. (unpublished data) collected
adults of this species at elevations ranging
from 1431 to 2969 m in the upper Arkansas
River in Colorado, from areas where substrata
range from boulder-cobble to gra\el-sand. In
New Mexico E. claripennis occurs in all north-
ein and westeiTi drainages in cool to cold waters
where substrata are predominantlv^ gra\'el-sand
(Sublette and Sublette 1979).

Steep rock faces at or near the water s edge
in Grand Can)'on, together with the occasional
patches of cobble-gra\el, proxide considerable
madicolous habitat and are the probable pi'c-
ferred habitat.

Distribution. — Holarctic; widely distrib-
uted in the Nearctic region; introduced into
Hawaii (Oliver etal. 199()).

\Iatki{ial kxaminkd. — AZ: Coconino Co.,
(irand ('anxon National Fark, Colorado Ri\er.
4 6 6. river mi 0.0, 947 m ele\'; 1 9 Fex, ri\er
mi 3.4, 945 m elev; 4 6 6, river mi 31.5, 876 m
elev; 1 6, river mi 31.8, 876 m elev; 1 9 Fex,
ri\er mi 34.1, 872 m ele\; 1 6 , ri\er mi 43.2,
861 m ele\'; 1 6 , river mi 61.5, 826 m ele\-; 2
6 6, rixer mi 65.3, 808 m ele\'; 1 6, river mi
98.0, 706 m elev; 2 6 6, ri\er mi 108.5, 664 m
elev; 3 6 6, river mi 133.0, 597 m ele\'; 1 6 ,
rixer mi 150.0, 556 m ele\-; 1 6, rixer mi
172.0, 521 m ele\-; 1 6, rixcr mi 204.0, 454 m
tle\ : 1 c?, I 9 Fex, ri\er mi 203.7, 451 m ele\.

Eukiefjerielld cocrulcsccns
(Kicffer)

Triclioflddiiis (■()cnilc.\(iiis kit'llcr, in /a\ rrl UJ2(i:279.

SpimiDloiiKi [EiikicffcricUiO cocniU-sccns (Kii'fk'r):

I'.cKwiids lf)29;:}.il, liciicric (siiliiii-iu'rici position, ivsicw,

(lisli iliiilioii.

1998]

(iKANn Canion ( JiiK()\()\iii) Taxonomy

121

Eitkiefferiella cocnilcsiTii.s (Kit'Oer): Bnmcliii KJoCrcST.
male, in key, generic position, clislrihutioii; Leluiuiuii
1972:369, male, pupa; Hudson et al. 1990:9, in list, distri-
liiition: Langton 1991:124, pupa.

Diagnosis. — In tlic adult thf pirscncc of
distinct inicrotrichia hftweeu the e\e facet.s
and a bare scjiiania are unicjue features among
Nearctic EuhicjfcncIIa. The pupa has a dis-
tinetiw eliaetota.xx as well as \c'r\ short anal
uiaerosetae, of which 1 is distinctK shorter than
the other 2 (cf. Langton 1991: Figs. 51a-c).

Discussion. — Nearctic material of" adults
and pupae agrees well with the descriptions
gi\en b\- Lehmann (1972:369) except that the
antennal ratio of the male is intermediate be-
tween that gixt'u for this spi'cies and E.
hocvrciisis Brundin. Langton (1991:124) has
redescribed the pupa (in a correction sheet he
has added that the pupa has a small, thin-
walled, saclike thoracic horn; this is ven' fre-
(luentK lost and thus in earlier descriptions
was described as lacking). Ovu" material agrees
well with his description.

EcoLocv. — Listed as a member of the
madicolous assemblage b\' Oliver and Sinclair
(1989) (see Eiidactylocladiiis dubitatiis, above),
E. cocntlcscois has also been taken h-om acjuatic
mosses (Ringe 1974, La\ille and Laxandier
1977, Nolte 1991) and has been found in
streams with organic enrichment (Cobo and
Gonzales 1991). Bode (1983) reported the
coerule.scens-group as apparentl\- w'idespread
in North America, occurring mostly in small to
medium-sized, unpolluted streams. Schmid
(1993) collected it in low numbers from the
surface and gravel interstices of a coldwater,
gravel-bottomed stream in Austria. In Ger-
many, Ringe (1974) obsened that adult emer-
gence in 2 small streams was essentially bivol-
tine but that the peaks of emergence were out
of phase between the 2 streams, with the
warmer stream having the main peaks of
emergence almost a month before the stream
with the colder more uniform temperatiues.
In the Fulda, Lehmann (1971) found this species
only in strongK' flowing water in moss or on
stones of the krenal to hyporithral regions.
Kownacki (1982) found this species at onK a
single station in a small upland stream in
Poland, occurring in an area of low current.
Mouxabed and La\ille (1983) reported this
species in Lebanon from 3 stream sxstems at
ele\'ations aboxe 1100 m, usualK on moss- or
algal-covered rubble. In the Ossau Valle\ of

the French Pyrenees, E. coendescens is one of
the more abundant species, occurring most
often in fast to ver\ fast streams from 500 to
2100 m elevation; maximum temperatures
range from 10° to 15°C (Laville and Vingon
1991). One of the most unusual occurrences of
E. coendescens was repoited in an nndergiound
stream of a cave system in Rumania some
8000 m from its epigyean source (Albu and
Stergar 1971). Adults have been taken in the
Arkansas Rixer of (Colorado at elcNations rang-
ing from 1431 to 1018 in, primarih from gravel-
sand substrata (Ruse et al. unpublished datii).
In New Mexico E. coendescens is found mostK
in the cool to cold northern and western
streams where gravel-sand substrata predomi-
nate; a record from the warm-water, lower
Pecos River was fiom a gravel substratum (Sub-
lette unpublished data).

DISTKIBLTION. — Ilolarctic; this species is
probably more widely distributed in the Nearc-
tic region than records indicate.

Material e.\.\mined. — AZ: Goconino Go.,
Grand Ganyon National Park, Golorado River,
1 9 P river mi 0.0, 947 m ele\'; 1 S , river mi
3.4, 941 m elev; 1 6, river mi 31.5, 876 m
elev; 2 6 6, river mi 43.2, 861 m elev; 1 6,
river mi 68.0, 808 m elev. In addition, we have
reared material from Arizona, Golorado, and
New^ Mexico.

EukiejfericUa dkleyensis
(Edwards)

(Figs. 36-.39)

Spaniotonm ilklctjcnsi.'i Edwards 1929:349: t\'pe local-
it\, llkle\, Yorkshire, England.

Eiikiejfcriclld ilkl('y('n.si.<i (Edwards); lehmann 1972:372,
re\ision, adult, pupa; Finder 1974:198 and Laville 1979:
161, ecology; Storey 1987:339, de\elopniental ecology;
Hudson et al. 1990:9. in list, distribution.

Nearctic males and pupae, which are con-
sidered here as conspecific with Piilearctic pop-
ulations, differ in some slight details. The follow-
ing descriptions define the Nearctic material.

Male. — Colonition: Almost entirelx' black-
ish brown; scutellum, humeral and pleural
areas yellowish; legs dark; abdomen blackish
brown with the narrow apices of T \TI and
\41I somewhat paler; genitalia dark. Antenna
with 13 flagellomeres. Antennal ratio 0.85-1.05
(10). Palpal proportions 62:101:101:164 fim.
Eyes reniform, without dorsal extensions; ocu-
lar ratio 0.68-0.73 (4). Glypeus rectangular,
much wider than long, slightly narrower at

122

Great Basin Natliiulist

[Volume 58

Figs. 37-39. Eukiefferiella ilklci/nisis. I'lipa: 37, llioiatit- lioni; .3.S, alKlomiiial sliamccn and cliarli)ta\\. Mclriociiciiuis
Stevemi. Male: .39, Kciiitalia (dorsal \ icw hdow, inlcrnal skeleton al)o\c).

1998]

Grand Canyon Ciiikonomii) Taxonomy

123

Ixise tliaii widtli of tlu> antennal pedicel; cl\p/
ped ratio ().S7-().93 (9j; cKpeiis with (1-8 (12)
setae. Temporal setae 2-5 (12), iisualK in a
small clump behind dorsal apex of the eye
(with 1-2 \er\ fine inner verticals observed in
2 specimens).

Thorax: Antepronotum slightK and almost
evenly tapered to the apex, collarlike. Tho-
racic chaetotaxN : lateral antepronotals 2-5 (5);
dorsocentrals 8-12 (5), set in paler aKeoli, in a
sintile row; acrostichials 7-13 (5), mostly in 2
rows; prealars 3 (5); supra-alars lacking; scutel-
lars 7-11 (5), mostly in a staggered single row.

Win^: Membrane with \ery fine micro-
trichia bareh' \isible at phase 50()X. (>osta ex-
tended 30-55 (6) |lm beyond R44.5, which ends
distinctl\- proximal to tip of M3+4. R2+3 t'uds
at 0.29-0.35 (5) of the distance betAveen apex
of Ri and R4+5. Venarum ratio 1.09-1.17 (5).
Wing length 1.90-2.37 (9) mm. Squama with
(5-13 (11) marginal setae. Wing vein setae: R
1-1 (5), Ri 0-1 (5), odier \eins without setae.

Legs: All legs with a single tibial spur; fore-
tibial spur length 48-58 (5) |im; middle tibial
spur length 38-46 (5) |im; hind tibial spur
length 54-70 (5) |im. Pub illi absent. Leg ratios:
P 1 0.60-0.66 (10); P II 0.48-0.55 (5); P III
0.57-0.61 (5). P III comb setae 12-14 (5). P II
and P III sensilla chaetica lacking.

Abdomen: Setae on terga II-IV broadly
strewn o\er most of each tergum except for a
posteromedian concave area devoid of setae;
terga V-VIII with setae strewn over most of
each tergum except for a narrow apical trans-
\erse band.

Genitalia (Fig. 36): Ninth tergum with 2-3
(10) setae. Virga absent. Gc/Gs ratio 1.80-2.06
(5).

Pl FA. — Exuviae: Exuxiae almost entireK
blown.

Ceplialotliorax: Frontal setae absent. Tho-
racic horn (Fig. 37), length 122-152 |im; apical
denticles on the basal enlargement \eiy weak
or perhaps absent in some specimens. Cephalo-
thorax almost smooth on either side of median
suture. Precorneal setae with 1 long and 2
smaller setae. Dorsocentrals siuall, almost in a
line, Dcj 5 larger, Dc.9 4 smaller Wing sheaths
without bacatifomi papillae or nasiform tuber-
cles.

Abdomen: Abdomen length 1.59-1.90 mm.
Shagreen pattern and chaetotaxy (Fig. 38).
Pedes spurii B lacking. Terga II-VIII with pos-
terior spines; T III-V' with a continuous row of

recurved hooks behind the spine row; hook
number: III 17-24, IV 18-24, V 12-18. Sterna
\'I and VII with inconspicuous apical denticles.
Tergum VIII with L124 ver\' fine; L3 larger
and heavier but not spinose. Anal macrosetae
of une(|ual length, with the medial 1 smaller
than the lateral 2; lateral macrosetal length
124-150 |lm.

Dia(;N()si.s and dlscussion. — Despite some
minor differences, this population is consid-
ered to be conspecific with the Palearctic E.
ilkleyensis (Edwards) and is very similar to the
Holarctic E. devonica (Edwards) in adult and
pupal stages. The adult differs in having the
ventral junction of the gonoco.xites irregularly
papillose and the apex of the phallopodeme
weakly digitate (not always clearly visible, be-
ing dependent upon the orientation of the
genitalia on the slide), while both Palearctic E.
ilkleyensis and E. devonica have a smoothly
rounded medial junction and the phallopodeme
is not illustrated as digitate (cf Lehmann
1972: Figs. 30, 34). Further, the temporal setae
of this population are usually restricted to
behind the dorsal apex of the eye while Pale-
arctic E. dkleyensis has a group of 3-4 setae
near the midline in addition to the group
behind the dorsal apex of the eye (cf. Leh-
mann 1972: Fig. 36). The antennal ratio is
much higher than in E. devonica.

The pupa of this species can best be distin-
guished by the different thoracic horn. In Pale-
arctic E. ilkleyensis the filament is short (cf.
Lehmann 1972: Fig. 37) to very short (cf Lang-
ton 1991: Fig. 51d), while in this population
the filament is distinctly longer; further, the
fine denticles at the base of the filament arc
usually distinct in E. ilkleyensis, whereas in this
population the denticles are ven sparse (visi-
ble only at phase 500X) or entirely absent.
Although the thoracic horn is nearer to that
illustrated for E. devonica (Lehmann 1972: Fig.
32), the filament, which is shorter than in that
species, and the absence ()f apical hooks on
sternum VIII clearly distinguish this species
from E. devonica.

EcoLOCY. — Eiikiefferiella ilkleyensis is a
member of the devonica -^roup. which is asso-
ciated with mosses and algae in small to large
rivers (Bode 1983). It has been found most
often on Ranunculus (Pinder 1980), Ranuncu-
lus and gravel (Pinder et al. 1987), or at^uatic
mosses (Ringe 1974, Nolte 1991). Armitage
and Blackburn (1985) reported the species at

124

Great Basin Naturalist

[Volume 58

stream sites with low /inc concentrations and
considered it to be intolerant in the pollution
tolerance codes of Wilson and McGill (1982).
However, Cobo and Gonzales (1991) collected
it on the Sar River in Spain at 1 station of 5
that received organic enrichment. Pinder and
Farr (1987) also reported it in low numbers
from a small chalk stream in southern England
at a station with elevated levels of organic
enrichment. In Poland in the River San, Kow-
nacki (1989) found this species to be one of
the dominants above a sewage outfall, but it
diminished or disappeared at downstream sta-
tions. Storey (1987) considered E. ilkleyensis
to be a scraper/herbivore that selectively feeds
on auRvuchs, especially epiphytic diatoms.
Tokeshi and Townsend (1987) described aspects
of the ecology of a population living epiphyti-
cally on MyriophyUum spicatwn L. in a small
river in eastern England. It was collected by
Schmid (1993) from a coldwater, gravel-bot-
tomed stream in Austria; lan^al densities were
low. Kownacki and Kownacka (1971) and Kow-
nacki (1982) foimd this species at several sta-
tions on small upland streams in Poland; how-
ever, greatest numbers were reported over
stony bottoms. Kownacki and Zosidze (1980)
and Kownacki (1985) also reported it from
medium to large, stony streams from the Little
Caucasus Mountains of Georgia (Adzhar) and
the Caucasus Mountains of Azerbaijan. In the
Alz River of Germany, Kownacki and Margrei-
ter-KowTiacka (1993) reported that this species
avoids slower cuiTents and softer bottoms below
a lake outflow but occurs conmionly in lower
stretches of the stream. In Lebanon, Moubaycd
and Laville (1983) reported E. ilkleyensis at
onK' 1 station on the Assi River, in fast current,
on rubble partially covered with mosses. In
the Ossau Valley of the French P\renees, this
is a rare species occurring in hist to slow
streams at elevations of 45()-5()() m; maximum
temperature is 15°C (Laville and Niiii^on
1991). Ruse et al. (unpublished data) found il
at only a single location in the upper Arkansas
Hi\er of (Colorado at an elevation ol 1431 in.

Disi uiBll l()\. — We ha\t' reaied material
honi sficanis in Arizona, (Colorado, and New
Mexico.

.VI All: RIAL L.\AMl\i;i). — AZ: Coconino (J).,
Grand Canyon National Park, (Colorado Hixcr,
266,5 6P,59 Pex, river mi 3.4, 94! in clc\ :
1 6 Pex, 1 9 Pex, river mi 34.1, 872 m cKx; 1

Pex. river mi 63.7, 818 m elev; I 6¥, river mi
74.3, 792 m elev; 1 6, river mi 75.3, 785 m
elev ; 1 6 , river mi 0.0, 947 m elev; 1 6 , river
mi 52.7, 846 m elev; 2 6 6, river mi 71.0, 808
m elev; 2 6 6, river mi 72.0, 796 m elev; 1 6 ,
river mi 87.5, 740 m elev; 1 6 , river mi 88.0,
739 m elev; 1 6, river mi 89.0, 736 m elev
(CAS, USNM, CNC, INHS, JES).

Eukiefferiella sp.

Diagnosis, discussion, and ecolocy. —
The adult is scarcely distinguishable from that
of E. ilkleyensis in genitalic features; however,
the tip of the antenna is broken off (antennal
ratio estimated to be about 1.0). The pupa is
readih' distinguishable bv' its distinctive thoracic
horn, which is more like that of E. devoniea
(Edwards) (Lehmann 1972: Fig. 32). Unfortu-
natelv, the presence of small hooks at the apex
of S VII (Lehmann 1972: Fig. 33) cannot be
ascertained, as the apex of the associated pupal
exuviae is missing beyond segment V

Material e.yamined. — z\Z: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 6 Pex, river mi 63.7, 818 m elev.

Limnophyes sp.

Diagnosis and discussion. — A single male
was taken, but during slide preparation the
genitalia were badlv crushed, hence the lack
of a specific determination.

Ecology. — The genus Limnophyes occurs
in mnnerous ecotopcs, ranging from aquatic
(particularly madicolous) to semiterrestrial
habitats.

Material e.vv.mined. — AZ: Coconino Co..
(hand Canyon National Park, Colorado Kivcr.
1 6, river mi 133.5, 600 m elev. 9-11-90.

Metrioeneiints stevensi
Sublette, new species

IIoloimm; viALi;. — AZ: (xKonino Co., Cirand
Canvon National Park, (iolorado River, Vaseys
Paradise, river mi 31.8, 876 ni elev, j.S. (C.\S).

Coloration: Head, thoracic \iltat'. prct-pis-
Icrnum, and i)ostnotum blackish brown; anti'-
|)r()n()(inii and scntcllnni paler than postnotum;
liiniicral and |)IcinaI areas Ncllowisii; legs and
abdomen dark brown.

Head: Antcmia with 13 llagcllonuTcs; iiilK
plumed. Antennal ratio 0.93. Palpal propor-
tions 47:195:172:211 |im. Eyes with dorsal ex-
tension short and wcdge-shapi-d. Ocular latio

1998]

Grand Cannon (."iiikonomii:) Taxonomy

125

0.15. C^Kpciis (iiiadiaiiUiilar. sliulitK wider at
base than width ol die antciiiial pcchcel (1.07);
with 22 (23; 1) setae, reiiiporal .setae 23 (31; 1),
those in the postoeular series coarse and in a
single row, wliile those King medial to the e\'e
hner, mnltiserial. and reaching to near nnclline

01 the head.

Thorax: .Antepionotnni rather broad and
collarlike, almost parallel-sided in the apical
half. Thoracic chaetotaxy: lateral antepronotals
7 (9; 1); dorsocentrals 53 (42; 1) (inclnding 15
[](■); 1] humerals), in 3 staggered rows posteri-
oil\. with the lunnerals becoming mnltiserial
antt'iiorh ; aerostichials abont 35 (37; 1), par-
tialK ill 2 lows; prealars 18 (23; 1); supra-alars

2 (2; 1): scutellars 32 (32; 1), in a single row
lateralK, becoming 3-4 rows medialK; pre-
episternals 9 (5; 1).

^r/nfj: Membrane with fine macrotrichia o\er
most of the membrane. Costa extended 170
' 120; 1) )im be\'ond R4+5. which ends slightK
distal to M3+4 at 0.21 of the distance between
apex of M3+4 and Mj^+2- I^2+.3 ^Iniw^t parallel
to Rj, ending at 0.14 of the distance between
its apex and apex of R4+5. Venarnm ratio 1.24
(1.23; 1). Wing lengtli 2.25 (1.92; 1) mm. Squama
with 17 (19; 1) marginal setae. Wing vein setae:
H 75, r-m 7, Rj 67, R4+5 128, M 24, M1+2 1^)4,
\l3+4 24, Cu 32, Cu^ 18, remigium 0.

Legs: Foretibial spur of holot\pe broken at
tip (54; 1) |im; middle tibial spur lengths 31/31
(34/28; 1) |im (tip of longer spur on holotype
broken); hind tibial spur lengths 53/28 (72/34;
1) Jim (extreme tip of longer spur on holotxpe
broken). PuKilli xestigial. Tarsal pseudospurs
present on Tai_3 of P II and P III (P III tarsi
missing on holot\pe). Leg ratios: P I 0.63; P II
0.43 (0.40; 1); PHI (0.44; 1) (P III lacking on
h()lot>pe). P III comb setae 11 (12; 1). P II and
P III sensilla chaetica lacking (P III tarsi miss-
ing on holot\pe).

Abdomen: Abdominal terga with scattered
setae; T IV with about 93 setae; sterna III-\T
with a midventral row of setae, that of S III uni-
serial, S I\' 2X with S V-\T nmltiserial; S
II-VI with mnltiserial laterals; S VII-\ III with
medial and lateral setal bands fused.

Genitalia (Fig. 39): Ninth tergum with 24
(21; 1) setae. Small virga present; length 24
|am. Gc/Gs ratio 1.78.

Diagnosis and discussion. — The combi-
nation of heavily haired wings, presence of
preepisternal setae, and extremeK' short anal
point is unique among Xearctic Metriocnenius.

Ecology. — The genus Mclriocncinit.s occurs
in a wide \ ariet\' of habitats, from madicolous
to semiterrestrial iiabitats.

NlArKHlAL K.VWIINKD.— Paralxpe (and holo-
type) 6, AZ: Coconino Co., Grand Can\'on
National Park, Colorado Ri\'er, mi 31.8, 876 m
elev LES (CAS).

This species is dedicated to Dr. Lawrence
E. Stexens who initiated and coordinated this
stucK.

Oiihocladiii.s (Etiortliocladiiis)
Iitteipes Goetghebner

Ortluiclddiiis httcipes Goetiilifhucr 1938:4.57; txpc
locality, Austria.

Ortliocladius (Eitorthoilcidiiisl httcipes Cioi'ttjlifhiRT;
Soponis 199();23. ri-xisioii. ;i(liilts and ininiatiircs, distrihu-
tiou.

Diagnosis .\nd discussion. — The adult
male and immatures have been separated in
key by Soponis (1990). Males are similar to
those of Ortliocladius (Eiiorthocladiiis) rivicola
Kieffer but may be recognized by the more
square-shaped basidorsal gonocoxite lobe
below which the basiventral gonocoxite lobe is
more weakly projecting than in O. rivicola;
however, the pupae are more distinctive than
the adults. It is probable that some males
identified in the literature as O. rivicola are
actualK' O. luteipes.

Distribution. — Palearctic; Oregon to New
\brk, south to Arizona and Georgia.

Ecology. — Orthocladius luteipes occurs in
creek and riverine habitats, spinning gelati-
nous cases on stones. This species' distribu-
tion broadK' oxerlaps that of O. rivicola.

Material e.\.\.\iined. — AZ: Coconino Co.,
(irand Canyon National Park, Colorado River,
1 6, river mi 3.4, 941 m elev, 24-VH-71.

Oi-thocladius (Euordiocladius)
rivicola Kieffer

Orthocladius riiicola Kieffer 1911:TS1; t\pe loealitx.
Germany.

Orthocladius (Euorthocladitis) rivicola Kieffer; Laville
1979;161, ecolog\'; Soponis 1990:26, revision, all .stages,
distribution; Hudson et al. 1990:11, in list, distribution;
Olixer et a). 1990:31, eatalog, distribution.

Diagnosis and discussion. — Soponis (1990)
has differentiated the adult and pupa of this
species from other Holarctic members of the
subgenus.

Ecology. — Orthocladius rivicola has been
categorized as "less pollution resistant" (Bazer-
que et al. 1989), although Cobo and Gonzales

126

Great Basin Natuiulist

[Volume 58

(1991) reported it at 3 of 5 stations receiving
organic enrichment on the River Sar in Spain.
In the high arctic Ha\es and Murray (1987)
found this to be one of the numerically domi-
nant forms that exhibited a bimodal emergence
during a 24-h study, with emergence continu-
ing o\ er the entire 6-wk stud\' period. Laville
and Laxandier (1977) also reported this as a
numerically dominant species all along the
length of a torrential brook in the Vallon d'Es-
taragne in the French Pyrenees. In the Ossau
Valley of the French Pyrenees this was one of
the "frequent or abundant" species in fast to
very fast waters at elevations of 500-1500 m;
maximum water temperatures were 12-15°C
(Laville and Vinson 1991). It has been reported
from aquatic mosses (Kownacki 1971, Nolte
1991) and from Cladophora in the aufwuchs
assemblage (Janko\'ic 1973). Mason and Lehm-
kuhl (1983) observed that numbers of this
species were not diminished downstream from
a dam when compared with upstream popula-
tions. In Austria, Schmid (1993) collected lai-vae
in low numbers from the surface and gravel
interstices in a coldwater stream, while Ander-
wald et al. (1991) took it from the Danube, a
large river. It has also been reported from the
lower Danube in the fonner Yugoslavia ( Janko-
vic 1973). Ringe (1974) illustrated an emer-
gence period from April to August in a small
stream in central Germany, with 1 major peak
of emergence occurring in early May; in the
Fulda, Lehmann (1971) reported the highest
abundance of this species in the strongly flow-
ing currents of the rhithral regions. Kownacki
(1982) found it to be most abundant in Poland
at a station on stony bottoms in an upper-ele-
vation Carpathian pastureland stream, while in
the high Tatras it was most often encountered
in rapid current in the montane forest zone
(700-1500 m elevation), being the dominant
species there (Kownacki 1971, Kownacki and
Kownacka 1971). Kownacka and Kownacki
(1972) clarified the dominant status to those
stations with a granite substratum below 1550
m elevation. In the medium to large stoin
streams of the Little Caucasus Mountains of
Georgia (Adzhar) and the Caucasus Mountains
of Azerbaijan, this species was among the
dominant chironomids (Kowanacki antl Zosidzc
1980, Kownacki 1985). In Rybi Potok, a po\-
luted stream in Poland, Kownacki (1989) found
that (). rivicola increased in abundance as
organic enrichniciit dc-creased. In (AMinan\,

Kownacki and Margreiter- Kownacka (1993)
collected it in the Alz River at all stations
including the soft-bottomed, slower-flowing
section immediately below a lake outflow; Reiss
and Kohmann (1982) collected it fi-om tlie banks
of the lower Inn River, a large, regulated, pri-
man' ti"ibutar\' of the Danube. Fiili\' (1975) found
highest numl)ers in low to intermediate flows
in a low-nutrient, stony stream in Ireland. This
is one of the more abundant orthoclads in the
Colorado River as well as the upper Arkansas
River in Colorado (Herrmann et al. unpub-
lished), and the upper Canadian, Rio Grande,
San Juan, and Gila drainages in New Mexico;
it occurs on a variety of substrata ranging from
boulder-gravel to sand-silt (Sublette unpub-
lished). Ruse et al. (unpublished data) col-
lected adults in the upper Arkansas Ri\er at
elevations ranging from 1431 to 3042 m.

Distribution. — Holarctic; widely distrib-
uted throughout much of North America from
the high arctic to the lower temperate zones.

Material ex.\mined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado Ri\ er,
4 6S,2 9¥,lFex, river mi 0.0, 947 m elev; 1
S , river mi 2.0, 945 m elev; 3 S Pex, river mi
3.4, 941 m elev; 1 6, river mi 20.4, 911 m
elev; 1 S, river mi 31.0, 876 m elev; river mi
31.5, 876 m elev; 1 6, river mi 43.2, 861 m
elev; 2 6 6, river mi 52.7, 846 m elev; 2 S 6 ,
ri\'er mi 53.0, 846 m elev; 1 6 , river mi 56.0,
838 m elev; 2 6 6, river mi 61.0, 826 m elev; 2
6 6 , river mi 63.7, 823 m elev; 2 6 6, river mi
65.3, 815 m elev; 1 6, river mi 88.0, 739 m elev;
1 6 , river mi 89.0, 736 m elev; 2 6 6, river mi
108.0, 699 m elev; 1 6, river mi 124.0, 625 m
elev.

Orthocladius (Orthocladiiis)
frigidus (Zetterstedt)

(■hironoiniis fri<ii(liis '/rttcrstcdl 1S3S;S12; t\pt' IoimI-
it\', ('.R'cnlancl.

Ortluxludius [Orthocladius) fri^idiis (Zettfistcdt):
Sopoiiis 19S7:123, siil)U(Mieiic' position, revit-w. s\iu)iiyiii\';
UJ90:.53, niorplioloUN ; ()li\cT et al. 1990:32. in lataloij;.

Diagnosis and discussion. — Soponis (1987)
has characterized all life history stages. Tht^
male genitalia are similar to those of some lucni-
bers of the subgenus EiiDrthocladius (Soponis
1990) in which (). frigidiis was. until recently,
included. llowt'Ncr, the anal point is usualK
distinctK broadci" and tlu' dorsal I'xlcnsion ol
the e\c' is longer than in members ol that sub-
gemis (Soponis 1990: iMg. 12).

1998]

Grand Canyon Ciiihonomid Twononh

127

ECOLOCY. — Orthoclddiiis fripdiis inliahits
cool to cold streams, constructing dctritus-
(Micrustcd silken tubes in moss or algae. It has
been reported on stones but seldom on moss
and algae in a small stream in central (Germany
(Ringe 1974), on ac^uatic mosses (Noltc 1991),
from "springs, streams and rivers" (Aagaard et
al. 1987), and in an islandic lake, primariK in
the littoral splash zone but occasionalK as
deep as 30 m (Lindegaard 1980). Armitage and
Blackburn (1985) found O. frigidus in streams
with moderate levels of zinc, but it is consid-
ered pollution intolerant in the classification
of Wilson and McCill (1982). Semi-Tosio (1977)
took it tioni a stream with considerable anthro-
pogenic emichment. while Cobo and (ionzales

(1991) reported it from 1 of 5 stations recei\-
ing organic enrichment on the River Sar in
Spain. In a Pyrenean torrent, d'Estaragne,
La\ille and Lavandier (1977) found this species
in small innnbers abo\e 2150 m elevation,
occurring on boulder- gravel substrata or on
moss. In the Ossau Valley in the French Pyre-
nees, this species had the highest frequency of
occurrence, occupying streams at elevations of
500-2000 m; water temperatures ranged from
9° to 16°C (Laville and Vingon 1991). Schmid

(1992) observed this species at significantly
higher densities in the main current channel
than in the marginal area of a graxel stream,
the Oberer Seebach, in Austria; he further re-
ported a tendenc)' towards bivoltinism. Ringe

(1974) illustrated 2 major peaks of adult emer-
gence from a small stream in central Germany,
1 in Ma\ and the other in November. Fahy

(1975) collected this species most often in inter-
mediate flows in a ston\', low-nutrient stream
system in Ireland. In the high Tatras of Poland
it occupied stony bottoms in rapid current
(Kowiiacld 1971, Kownacld and Kownacka 1971);
in the Little Caucasus Mountains of Georgia
(Adzhar) and in the high Caucasus Mountains
of Azerbaijan it was taken from sexeral stations
in medium to large, stony-bottomed streams
(Kownacki and Zosidze 1980, Kownacki 1985).
In German}, Kownacki and Margreiter-Kow-
nacka (1993) found this species in the Alz River
most often some distance below a lake outflow;
Lehmann (1971) reported it from the Fulda in
areas with strong currents; and Reiss and Koh-
mann (1982) collected it from the banks of the
lower Inn River, a regulated, primary tributar>'
of the Danube. In Lebanon, Moubayed and
Lax'ille (1983) reported O. frigidus from sev-

eral stream SNstems with xariabic current and
substrata, but usually at stations with mosses or
macrophytes. It has been taken at elevations
from 1746 to 3042 m on gravel/cobble sub-
strates in the Arkansas Hi\er of (Colorado (Ruse
et al. unpublished data). The rarity of O.
frigidus in the Colorado River is possibly due
to the almost constant scouring action of the
ri\er in the canyon, which disturbs the pre-
ferred gra\el and remo\es algal clinnps.

Distribution. — Holarctic; in North Amer-
ica this species occurs from California to New
Mexico and Colorado, PemisyKania, and
Greenland.

M.VIERIAL E.XAMINED. — AZ: Coconino Co.,
(irand Canyon National Park, Colorado River,
1 L, river mi 0.0.

Orthocladius (Orthocladius)
mcdlochi Kieffer

Orthochidius lartcipcnni.s Malloch 191.5:524. male:
hpe localiU-, South Haven, MI.

Orthocladiu.s mallochi Kieffer 1919:191, nomen iiovtun
for Orthocladius lacteipennis Malloch 1915, non Lund-
stroni 1910.

Orthocladiwi (Orthocladius) mallochi Kieffer; .Soponis
1977:6.3, revision, adults, immatiires, distribution; Savage
and Soponis 1983:302, adult morphoIog\: Hudson et al.
1990:11, in list, distribution; Oliver et al. 1990:.32, in cata-
log, distribution.

Diagnosis and discussion. — Adults and
immatures ha\'e been ke\ed b\' Soponis (1977).

Ecology. — Orthocladius mallochi was one
of the rarest Orthocladiinae in a brown-water
stream in Alberta, with only 0.03 of 1.0%
males/m^/yr collected (Boerger 1981). It is
common in the upper Arkansas River of Col-
orado where it occurs at elevations of 1431-
2905 m (Ruse et al. unpublished data). It occurs
in most stream sxstems in New Mexico (Sub-
lette unpublished).

Distribution. — This species has an unusual
distiibution, with specimens taken from Alberta
south to C^alifornia and New Mexico in west-
em North America and from .Northwest Terri-
tories south to Illinois and South Carolina in
the East.

Material e.\.\mined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 6 , river mi 204.0.

Paracladius conversus (Walker)

Chironomus conversus Walker 1856:175; t\pe locality,
British Isles.

Paracladius conversus (Walker); Hin enoja 1973:94, re-
\ ision, adults and immatures; Sublette and Sublette 1979:

128

Grkat Basin Nati'r.\l!st

[Volume 58

80, clistrihutioii; Oliver t-t al. 199();o3, in catal()<4. distribu-
tion.

Diagnosis. — The adults and pupae of the 3
known species have been separated in ke) h)'
Hirvenoja (1973). Reared material from New
Mexico agrees well with Ilinenoja's descrip-
tions as does the single male taken in Grand
CauNon.

Ecology. — Paracladius cunvcrsus is most
frequently collected from lakes but is also
known from slow-mo\ing streams (Hirvenoja
1973). In German), Reiss and Kohmann (1982)
collected it from stream margins of the lower
Inn River, a large, regulated, primaiy tributary
of the Danube; in the Fulda, Lehmann (1971)
reported it from the Potamal region ("Barben-
region"). In the Nida River in Poland, Kow-
nacki (1989) found this species to be generally
distributed but occurring in greater abundance
in the recoveiy zone below a sewer outfall. It
is known from a zinc-contaminated stream
where it constituted <0.59c of the sample (Wil-
son 1988). It has been statistically associated
with MyriophyUiim in the River Pang in Eng-
land (Ruse 1992). In the Ossau Vdley of the
French Pyrenees this was a rare species, occur-
ring in medium to slow streams at 800-850 m
elevation; maximum water temperatures were
16° to 18°C (Laville and Vinson 1991). In small,
interrupted stream systems of Lebanon this
species was found at 3 stations with macro-
phytes (Moubayed and Laville 1983). In New
Mexico it was often taken near stream margins
(Sublette and Sublette unpublished data).

DiSTRiBLTiON. — Arizona to New Mexico
and Colorado; Pennsylvania. It is possible that
some records oi P. alpicola (Zetterstedt) from
the Nearctic region are actually this species.

Mati:rial IvVWIINKD. — AZ: (^oconino Co.,
(irand Canyon National Park, Colorado l^ixcr,
2S6, river mi 246L, 365 m elev, 13-.\i-1975.

Parakiejfcriclla suhatcnhiui
(Malloch)

(FiKs. 40-43)

C.ainplixlddiiis sulxilcrriiims Mallijcli 1915:512, male;
tvpe localilx', hank ol Mississii^pi Ri\i-r. (irand Tower. II.

(Inhs).

PaidkicffcriiHa lonildia S;etlier 19(19:138, male with
a.ssoeialed pupal and larval e.xuviae; type loeality. White-
shell Park, Vlanitoha, diteh.

Mariclddius sulxilcrriniiis (Malloeli); Sui)l(lle 1970:S."i,
jienerie position, review.

I'drakicfjcriclla .siihutcrriiiKi i\la!loclil: (.'ranslon and
Oliver 1988:44.3, j^enerie position, review, sviionvniv, dis-
tribution.

I'drakii'lfcriclla siilxitcrriiiid (Malloelij; Oliver et al.
1990:33, in catalog, distribution.

Di.\c;nosis a.\d discussion. — The male can
be recognized by the presence of a distinct
R2+3 which becomes evanescent apically, an
antennal ratio usualK' about 1.0 (0.68-1.34),
and, above all, the male genitalia. The genitalia
(Fig. 40) have typically a bluntly acute anal
point; compression due to more or less flatten-
ing by the cover glass results in considerable
variation in appearance of the anal point as
well as the basidorsal and basi\ entral gonocox-
ite lobes. Proximally, the basidorsal gonocoxite
lobe usually has visible a transverse apodeme
that appears as a darkened bar. Northern spec-
imens have a higher number of anal point setae
and higher antennal ratio (based on Sicther
1969).

The pupa, based on extensix e rearings from
New Mexico, differs in some features from
that described by Sagther (1969): the frontal
apotome has small frontal setae (Fig. 41), there
is a small egg-shaped thoracic horn with fine
apical denticles present (Fig. 42), pedes spurii
B are present on T II and III, and the sha-
green pattern on the abdomen is much weaker
(Fig. 43). Specimens from the Chama Rixer in
New Mexico near the Colorado state line ha\ e
heavier shagreen than those taken Irom the
Rio Grande in Dona Ana Count)' in New Mex-
ico near the Te.xas state line. Thus, the pupa
described from .Manitoba (Sicther 1969) with
the terga almost completely covered b\ sha-
green may represent the extreme of a north-
south cline.

Ec()1X)(;y. — This is a coniiuon inhabitant ol
the upper Arkansas Ri\cr in Colorado, found
at ele\ations ranging Irom 1444 to 2771 m
(Huse et al. impublished data).

DisTlUBUTlON. — Northwest Territor) east
to (Quebec and south to California and Illinois.

M.viKHiAi, K.XAMiNKD. — AZ: Coconino Co.,
Grand Cainon National Park, Colorado Ri\t'r,
1 6, river mi 89.0, 732 m elev, 8-1-91. Other
material examined: Calilornia, Colorado, New
Mexico, and I'tah.

I'dnDiKiriocncmii.s liiiulhcckii
( johannsen)

MiiriiiiiKiiiii.s htiitllntkii loli.iniiscn 19( ).">:. 302. uoiiun
noniiii lor ('liiroiioiniis iidiiii.^ Lundln-ik 1898:28,5, iion
Meigen 1818; ty|H- loealitv, (iri-eulaud: Oliver et al. 1990:
.') I, in eal.iIoLi. dislril)u(ion; I'plcr I995;(i.(i5, larva, distrib-
nliou.

199S]

GiuND Canyon CiiiKONOMin Taxonomy

129

41

42

KiiTs. 40-43. Parakiejfcriella sithaterrima. Male: 40. genitalia. Pupa: 41. frontal apotome; 42, thoracic horn: 43. abdomi-
il chaetotiL\\- and shagreen, including details of anal lobe and ape.x of anal lobe.

Parametriocnemus lundhecki (Johannsen); Sublette
1967:537. re\ie\v; Saethcr 1969:115, review, synonymy,
distribution; Simpson and Bode 1980:56, larva, ecology;
Cranston et al. 1983:261. Ian a: Simpson 1983:320, ecol-
og>-; Coffman et al. 1986:265. pupa: Cranston ct al. 1989:
310. male: Hudson et al. 1990:11. in list, distribution.

Diagnosis and discussion. — The adults
and pupae ha\e been well eharacterized In
Siedier (1969).

Ecology. — ^The North Carolina biotie inde.x
(NCBI) value for Paratnetriocnemus hmdheckii
is 3.7 (Lenat 1993), which agrees with the
Simpson and Bode (1980) observation that the
species is restricted to relati\el\ clean water. It
has been listed b\ Singh and Harrison (1984)
as ha\ ing 3 periods of adult emergence, but
the species was not commonK' taken, compris-
ing onl\- 1.84% of all chironomids collected; this

130

Great Basin Naturalist

[Volume 58

was similar to Boerger's (1981) findings, which
listed only 0.5 of 1.0% males/nWyr of the total
Orthocladiinae. The cohort growth is asyn-
chronous with maximal growth in the spring
(Berg and Hellenthal 1992a). Beckett (1992)
collected the species in a large temperate river
on artificial plate samplers in low numbers
during most months except June-August. P.
lundheckii was more frequently taken from an
acid, poorly buffered Precambrian Shield stream
with a boulder-cobble bottom covered with
thick growths of Fontinalis (Rempel and Harri-
son 1987). McShafFrey and Olive (1985) found
only diatoms in the gut contents of larvae. In
the upper Arkansas River of Colorado this is
an uncommon, but rather widely distributed,
species occurring at elevations ranging from
1444 to 3042 m (Ruse et al. unpublished data).
In New Mexico P. lundbeckii is widely distrib-
uted in northern and western cool- to coldwater
streams (Sublette and Sublette 1979). Epler
(1995) reported the larvae as being sensitive to
organic pollution.

Distribution. — Alberta east to Quebec and
Greenland, south to California and Florida.

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 6, river mi 133.5, 625 m elev, 17-VIII-75.

Paraphaenocladius exagitans
(Johannsen)

Metriocnemus exagitans Johannsen 1905:303; type
locality, New York.

Paraphaenocladius exagitans (Johannsen); Sublette
1967:543, review, generic position; Hudson et al. 1990:12,
in list, distribution; Oliver et al. 1990:34, catalog, distribu-
tion, synonymy.

Diagnosis and discussion. — The hairy
wings, retracted R4+5 ending proximal to the
apex of M3^4, and features of the male geni-
talia (Sublette 1967: Figs. 36, 37) differentiate
this species from other Nearctic congeners.

Ecology. — Members of this genus in the
Palearctic region are reported to be terrestrial,
living in damp soil adjacent to water bodies
(Strenzkc- 1950). In the Nearctic, however, "at
least semiac^uatic and perhaps truly acjuatic
species occur in streams and springs" (Cranston
et al. 1983). Rosenberg et al. (1988) ri-ported
Paraphaenocladius exagitans emerging IVoni a
fen in western Ontario, indicating at least a
semiaquatic existence for this species. Ruse et
al. (unpublished data) collected this species

only once along the Arkansas River in Colo-
rado at an elevation of 2338 m; adults proba-
bly came from nearby spring seeps or marshy
areas.

Distribution. — South Dakota east to New
York, south to Arizona and New Mexico.

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 6 , river mi 31.8, 876 m elev; 1 6, river mi
124.0, 625 m elev.

Pseudosmittia nanseni

(Kieffer)

Psectrocladiiis nanseni Kieffer 1926:82; t\pe localit\,
Ellesinere Island, Northwest Territories.

Prosmittia nanseni (Kieffer); Oli\er 1963:177, generic
position, in list; Siether et al. 1984:270, review of holotvpc.

Pseudosmittia nanseni (Kieffer); Cranston and Oliver
1988:451, generic position, added description of male, dis-
tribution; Hudson et al. 1990:13, in list, distribution.

Pseudosmittia n. sp.l; Sublette and Sublette 1979:83,
misidentification, distribution.

Diagnosis. — The male genitalia (Saether et
al. 1984: Fig. 12; Cranston and Oliver 1988:
Fig. 20) are distinctive. Immature stages are
unknown.

Discussion. — This wide-ranging species
shows considerable variation between north-
ern and more southern populations (Cranston
and Oliver 1988). Dr. O.A. Si«ther, Uni\ersit>
of Bergen, suggests the nominal species is
actually a complex of related forms (personal
communication).

Ecology. — Pseudosmittia nanseni is proba-
bly a madicolous species, as Wrubleski and
Rosenberg (1990) reported low numbers of it
from emergent vegetation where apparenth' the
aquatic-terrestrial interface proxides a habitat.
PresinnabK, wet algal strands in the splash zone
on the rock faces of the canyon wall in Grand
Canyon are similar to the interface foimd on
emergent acjuatic xegetation.

DisiHUH riON. — Alaska to Greenland, south
to (California, east to Georgia.

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado Ri\er,
1 6 , river mi 6.0, 945 m elew

Tvetenia ritracies
(Scether)

F.ukicfftriilla t ilracits Sa'thcr 1969:49. male, icmalc.
and pupa.

Tfctenia litrarie.s (S;ethei); Sa'thcr ami llaKoist-n
1981:271, generic position; (Hoffman ct al. 1986:293. pupa.

Tvetenia raliesretis (Edwards); Sublette and Sul)lette
1979:74, re\iew, distribution, niisidentiiication.

1998]

Grand Canyon C'iiikonomii) Taxonomy

131

Diagnosis and discussion. — The .uenitalia
are ver>' similar to tliose of Tvcienia cahcsccns
(Edwards), T. discoloripe.s ((ioetuliehuer), and
T. havarica (Goetuhehuer) (ef. Pinder 1978:
Figs. 105 h, e; Leliniann 1972: Figs. 65, 70, 71,
77); ho\ve\er. the aiiteniuil ratios of jT calvescens
(Edwards) and T. Inivarka (CA)etuhel)uer) are
much lower (0.6-0.8 \s. 1.03-1.35). The pupal
thoracic horn and abdominal chaetotaxy of T.
lit rack's ha\e been briefl\- described b>- Siethei-
(1969) and figured b\- Coffhiann et al. (1986:
Fig. 9.75). It is \er)' similar to that of T. veiralli
(Edwards) (Langton 1991), but the pupa of
that species lacks the fine-pointed spines at
the ape.x of the anal lobe. The adult male of T.
icrralli has nuich stronger crista dorsalis on
the gonostxlus (cf. Pinder 1978: Pig. 105A).

Ecology. — Larvae of the discoloripes-gvoup
are most frequentK found in larger, warmer
ri\ers, most often in association with CJado-
phora (Bode 1983). Ruse et al. (unpublished
data) collected T. vitracies in the upper
Arkansas River of Colorado at elevations rang-
ing from 1497 to 1879 m.

DiSTRiBLTlON. — Arizona, California, Colo-
rado, New Mexico, Ontario, and Saskatchewan.
Possibly, some of the North American records
of T. calvescens are actually this species since
the male genitalia appear to be virtualK indis-
tinguishable.

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,

5 6 6, river mi 31.5, 876 m elev; 666, river
mi 31.8, 876 m elev; 1 6, river mi 43.0, 861 m
elev; 3 6 6, river mi 94.9, 715 m elev; 266,
ri\er mi 61.0, 826 m elev; 1 6 , river mi 123.0,
632 m elev; 1 6 , river mi 135.0, 594 m elev; 2

6 6 , river mi 186.0, 491 m elev; 1 6 , river mi
204.0, 454 m elev; 1 6, river mi 225.0, 411 m
ele\'.

Subfamily Chironominae

Tribe Chironomini
Apedilum subcinctinn Townes

Apecliluni suhcinctum Towiies 1945:33; t\pe locality.
Reno, N\'; Epler 1988:112, re\ie\v, generic reassignment;
199.5:7.24. lar\a, distiibution; Hudson et al. 1990:26, in list,
distribution.

Paralaitterhoniiclla suhcincta (Townes); Pinder and
Reiss 1986:418. pupa.

ParalauterhornicUa suhcincta suhcincta (Townes); Batli
and Anderson 1969:172, larva.

Diagnosis and discussion. — The male is
recognized most readily by the features of

genitalia (cf T)wnes 1945: Fig.24; Epler 1988:
Fig. le-k). The pupa has been characterized
b\ Pinder and Reiss (1986) and Epler (1988).

Ecology. — Apedilum sul)cinctinn lives in
ac^uatic vegetation, including mat algae. It
sometimes bi'comes a pest in concrete-lined
irrigation canals.

Distribution. — California to Ontario, south
to Jalisco.

Material ex.\mined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 6, river mi 61.0, 826 m elev; also, material
from California, Colorado, New Mexico.

Chir())i()i)ius deconis
Johannsen

Chironninus cU-conis Johannsen 1905:239; type local-
it), Itliaca, N^'; adults and immature stages.

CJiironomus dccorus Johannsen; Sublette and Sublette
1979:86, review, distribution; Martin et al. 1979:131, kary-
ot\pe.

Diagnosis and discussion. — The male
genitalia (Townes 1945: Fig. 136a), together
with abdominal coloration consisting of sad-
dle-shaped darker markings on terga II-V
(heaviest on II-IV, occasionally evanescent on
V) and a foretarsus without a beard, will differ-
entiate the species. However, there are at least
10 Nearctic species in this complex (Martin et
al. 1979), and identifications are somewhat un-
certain at this time. One of the authors (JES)
has examined the holot\pe at Cornell Univer-
sity, and the Grand Canyon material cannot be
separated from it on adult morphology. The
larva and pupa cannot be adequately separated.
The most reliable separation remains through
karyological examination.

Ecology. — Chironomus decorus is primar-
ily lentic but occurs wideh' in stream sxstems
in back-water pools and river stretches with lit-
tle current. As do other members of the genus,
this species lives on soft, muddy substrata,
occasionally on sandy-silt. In New Mexico it
occurs in ever\' major stream system in the
state (Sublette and Sublette 1979).

Distribution. — Throughout much of North
America; however, many of the literature rec-
ords of this and its junior synonym, Chirono-
mus attenuatus Walker, are suspect. Kan'ologi-
cal or DNA studies are needed to define the
many populations.

Material ex.\mined. — AZ: Coconino Co.,
Grand Canvon National Park, Colorado River,

132

Grka'I' Basin Natuiulist

[\olunie 58

1 S, river mi 259.0R, 8-\-9(); 1 6, rixer mi
268.5, 21-VII-75, LES.

Chir())u>mii.s i('hir())U)i)iii.si dccorus
Johaiinseii complex

At least 2 additional species of this group
occur in Grand Canyon, based on males with
adequate genitalia visible in limited slide-
mounted material. Hovvexer, this material was
not considered sufficient upon which to base
new species descriptions. With additional
material in hand a better appraisal will l)e pos-
sible. The localities for these are described
below

Clurononuis n. sp. 1

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado Ri\er,

2 6, river mi 246.0L, 13-XI-75; ? 1 ?, Pe.x,
river mi 209.0L, 4-XII-91.

Chirononuis n. sp. 2

Material examined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
1 c?, river mi 269.5, 21 -VI 1-75.

Chironomus (Chironomus)
iitalicusis Malloch

ChiroiKimii.s iildlwiisis Malloch 1915:438; t\pf lotalitN,
Kaysvillc, UT; Schaller and English 197(i;300, cytolog\ ;
Sublette and Sublette 1979:89, distribution; Martin et al.
1979:139, kaiyot\pc'.

Tcndipes (Tciidipcs} iifalicitsis (Malloch); Townes 1945:
127, review.

Chironoiniis (Chironointis) iildliciisis Malloih; ()li\ti
et al. 1990:43, distribution; Wiilker et al. 1991:71, review,
ininiatures and adults, karyosystenuitie position.

Diagnosis and discussion. — The distinc-
tive male genitalia will serve to differentiate
this species from other Nearctic species (ef
lownes 1945: Fig. 143). Immatures have been
characterized by Wiilker et al. (1991 ).

Ec:oLO(;v. — Ciiironouui.s iitdltciisis is pri-
marily lentic, inhabiting water bodies ranging
from large lakes and reseiAoirs to shallow ponds
in Nhmitoba and pla\a lakes on the l.lano
Estacado of New Mexico. I'his species is an
unconmion inhabitant of pool cm ironnients
with silty sand substrata; it also may occur in
backwaters. Similar collections ol the Iculic ('.
dccorus complex ha\f been taken in the
Arkansas liiNcr in Colorado and Pecos i{i\c'r
and I^io (irandc in New Nh'xico (Sublcllc un-
published data).

DisruiBLTiON. — This wideh distributed
western species ranges from Alberta and Man-
itoba south to California and New Mexico.

Material e.vwiined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado River,
\ S ,\ S Pex, 1 Lex, river mi 53.0, 847 m elev;
? 1 9, river mi O.OR, ll-VII-9(), J.S.; ? 1 d, L,
Pex, river mi 31.0R, 1-II-90. j.S.

Cijphomclla gihbera
Si^ther

C'l/phiiinclld <^il)l)('r(i S;ethcr 1977:103; t\ pe loealit\'.
Yankton, SD, male, pupa; Finder and Heiss 1986:379, pupa;
Oliver et al. 1990:45, distribution.

Diagnosis and discussion. — The male is
very near CyphinneUa cornea Seoiher in geni-
talic features but differs in having 8-11 setae
on the inferior volsella while C. cornea has
0-1; the superior volsella lacks setae while in
C. cornea there are usualK' 4 (cf. Siether 1977:
Figs. 37D, F). Immature stages have been fig-
ured by Siether (1977: pupa. Fig. 37A, B; larva,
Fig. 38; Pinder and Reiss 1983: larva. Fig.
10.13) as CyphomeUa sp.

Ecology. — Ruse et al. (unpublished data)
collected this species in the upper Arkansas
River of Colorado at an elevation of 1497 m.
In New Mexico this species occurs in a wide
\'ariety of habitats ranging from cold- to warm-
water streams with substrata ranging from
gravel to sand-silt (Sublette and Sublette
1979).

Distribution. — Saskatchewan and South
Dakota south to Arizona and New Mexico.

Material examined. — AZ: Coccmino Co.,
Grand Can\on National Park, C'olorado Ri\er,
2 LL, river mi 61.0, 826 m ele\; 1 L, ri\er mi
87.5, 740 m elev; 1 L, rixcr mi 187.5, 488 m
ekn; 19-IX-91, M.S.

rluiciKipsccIrd proftisd
(Townes)
(Figs. 44-18)

rdnyldisiis {'I'dni/ldr.^nsi profiisii.s Townes 1945:7.3; t\ pe
loealitN, Reno, NX. ni;ilc.

I'lidcnopsccird prujusd (Townes); (irodli.nis 1987:137.
generie iiosilion, morphology ecologx ; ( )ll\er el al. HJUO:.")] ,
dislribntion.

rluui,ops,;tni n. sp. 1: Sublcllc :md Siibl.tlr I979:l();5.
dishibutiou, misidcniilicadon: Martin ct al. 1979:1.51,
k;ir\ ()t\ pe.

Tlic ni;ilc has been briclK dcst libccl 1)\
Townes (1945). Ihe lollowiug is gi\cn to sup-
pKnient his description.

1998]

(iUAM) (:a.\U)\ c;iiiiu)\()mid T.woxomv

133

Figs. 44—48. Phaenopscctra profusn. Mali-: 44, genitalia. Pupa: 45, k'rmini \\: 4fi, tergimi \'l: 47. tcTgiim \'III.
Polypecliluiii iPolypedilinn) obelos. Pupa: 4S, irontal apotome.

Male. — Coloration: Head, thonix, and abdo- largely dark with the posterolateral margin.s of
men largeK l)lacki.sh browii; .scutellum some- the terga paler brown; genitalia infuscate.
w hat paler lirown; legs with coxae daik, remain- Head: Antenna with 13 flageUomeres. An ten-
der mosth stramineous except kniees, which are nal ratio 1.9-1.96. Palpal proportions 70:164:
slightK darker; haltere knob pale; abdomen 179:289 |im. Eyes with dorsal extension long

134

Great Basin Naturalist

[Volume 58

and parallel-sided. Ocular ratio 0.19. Clypeu.s
quadrangular, slightly longer than wide, with
21-23 setae; clyp/ped ratio 0.76. Temporal setae
14, in a single row, reaching about hall\\'a>'
from the dorsal apex of the eyes to the midline
of the head.

Thorax: Antepronotum greatK' narrowed
near the dorsal apex and closely appressed to
the mesonotal continuation (cf. Townes 1945:
Fig. 230). Thoracic chaetotaxy: lateral antepro-
notals lacking; dorsocentrals 16-18, in a par-
tial double row; acrostichials 15-16, mostly in
2 rows; prealars 7; supra-alars lacking; scutel-
lars 24-32, in a strewn pattern.

Wing: Membrane with heavy macrotrichia
distal to the apex of R| and with sparse macro-
trichia extending almost to the wing base. Costa
not extended beyond R4+5, which ends con-
siderably distal to M3+4 at 0.93 of the distance
between apex of M3+4 and M^+2- R2+3 (close-
ly parallels Rj, ending at about 0.2 of the dis-
tance between apex of Rj and R4-|-5. Venarum
ratio 1.0-1.04. Wing length 2.75-2.79 mm.
Squama with 15-18 marginal setae. Wing vein
setae: R 27, R^ 35, R4+5 63, M1+2 48, M3+4
21, Cui 19, An 25.

Legs: Foretibial scale with a minute spine,
very similar to that illustrated by Townes (1945:
Fig. 249); middle tibial combs with a single
spur; hind tibial combs with 2 spurs, of which
1 is slightly shorter than the other. Pulvilli con-
spicuous, almost as long as the claws. Leg ratios:
P I 1.10-1.15; P II 0.57; P III 0.73.

Ahdoiiu'ii: Abdominal tergal setae scattered,
becoming denser at the lateral margins.

Genitalia (Fig. 44): Ninth tergum with 12-16
setae. Gc/Cs ratio 0.95.

Pupa. — Cephalothorax: Cephalothonix brown;
wing sheaths mostly pale but outlined with
brownish margins. Frontal setae present on the
frontal tubercles very similar to that illustrated
for P. flavi))('.s (Meigen) (cf.Pinder and Reiss
1986: Fig. 1().59A); frontal setal length 58 |im.
Thoracic horn base also similar to that of
P. flavipes (cf Pinder and Reiss 1986: Fig.
10.59(>'). Median suture with strong tubercles
on either side near the anterior end and with a
smaller patch near the posterior end on either
side. Precorneal setae very weak, with 1 longer
and 2 slightly shorter setae. Posterior dorso-
centrals small, in a line below tlu' posterior
tubercle patch; anterior dorsocentrals not dis-
cernible. Wing sheaths without bacatilorm pa-
pillae or nasiform tubercles.

Abdomen: Abdomen mostK pale but with
blackish spots at the corners of conjunctiva
I-II, II-III, III-IV, and IV-V; lateral margins
of terga V-VIII with a narrow brown band
that becomes progressiveK' broader posteriorK*.
Abdomen length 4.85-5.00 nun. Shagreen pat-
tern and chaetotaxy very similar to P. flavipes
(cf Pinder and Reiss 1986: Fig. 10.59D), but
with the anterior band of shagreen not con-
spicuously heavier than the posterior; tergum
IV (Fig. 45), tergum VI (Fig. 46), and tergum
VIII (Fig. 47). Pedes spurii B on terga I and
II. Tergum II hooks 69-72 in a single row.
Anal lobe with 27-42 swim fringe setae.

Diagnosis and discussion. — The male of
this species is only weakly separated, based on
color features, from the closely related P. obe-
diens (Johannsen) (Townes 1945). These 2
species ma\ pro\ e ultimately to be conspecitic
when more material is available for examina-
tion. The pupa is very similar to P. flavipes but
differs in having a more heavily tuberculate
cephalothorax.

Ecology. — Grodhaus (1987) took Pliae)io-
psectra profiisa from temporary pools in Cali-
fornia and suggested that the species maintains
itself in permanent waters and opportunisti-
calh' invades temporary- pools, since it also has
been found in rice fields, resenoirs, and sew-
age lagoons. Ruse et al. (unpublished data)
collected adults of this species in the upper
Arkansas River of Colorado at ele\ ations rang-
ing from 1431 to 2944 m. Its rarity in the Col-
orado River in Grand Canyon bespeaks a
paucity of lentic habitats, principally small
back-Nvater and side pools.

Distribution. — Washington to Montana
south to California and New Mexico.

Material e.vwiined. — AZ: Coconino Co.,
Grand Canyon National Park, Colorado Ri\'er,
1 Lex, Pex, 6 , river mi 31.8, 876 m ele\'; 1 Pc?,
3 LL, river mi 53.0, 847 m elev; 2 LL, rixer mi
225.0,411 melev

Poh/pcdiliiDi (Tripodura^ ohclos

Sublette & Sasa

(Figs. 49-52)

l',ilillH(liliiiii r/i//)c/().vl(»/><7().v Siil)Ii-lt(.- \- Sasa 1994:50;
Ispc lotalilv, La\a(lci()s. ( iualciiiala, male and icinaU'.

in I'A.— 'Ibtal length 4.67, 5.52 nun (2).

Cephalothorax: I'Vontal apotome without
tubercles (Fig. 48); frontal setal length 62 |Hm.
Thoracic horn with 3 jiostcMior branches and
about 5 aiili'rior branclu'S, similar to that of

1998]

Grand Canyon Chironomid Taxonomy

135

51

49

Figs. 49-.53. Polypcdilum iPolijpcdilum) nbelos. Pupa: 49, terga III (above) and V'l (l^elow) shagreen and chactotaxy;
50, posterolateral spur of tergum V'lII. Larva: 51, antenna; 52, mentum and ventromental plate. Cladotanytar.sus
(Cladotanytarsiis) marki. Male: 53, genitalia.

136

Great Basin Natur.\list

[Volume 58

Pulijpcdihim (Tripocliira) cpomis Sublette aiul
Sasa (Sublette and Sasa 1994: Fig. 170). Pre-
corneal setae 2, 52 ^ini in length, snl)equal.
Median suture with moderate tubercles ante-
riorly on either side; posteriorly becoming
weakly rugose. Dorsocentral setae minute,
anteriorly with DcSj and DcS2 contiguous
and posteriori)- with DCS3 and DCS4 the same.
Bacatiform papillae and nasiform tubercles
lacking.

Abdomen: Abdomen length 3.48, 4.15 mm
(2). Tergum I with weak reticulation; PSB I and
II present. T II apical hooks 54, 62 (2). PSA
present on S IV-VI. Terga Ill-V shagreen as
in Figure 49; T VI with weaker shagreen so
that the anterior, medial, and posterior trans-
verse bands are separate. Intersegmental mem-
brane II/IV and IVA^ with weak shagreen (Fig.
49). Lateral abdominal setae: II-IV with 3 fili-
form setae, V-VI with 3 lamellate setae, and
VII-VIII with 4. Posterolateral spur of T VIII
(Fig. 50). Anal lobe with 38, 42 (2) fringe setae.

Larva. — Head capsule yellowish except for
tips of mandibles, mentum, and occipital ring.
Ventral head length 160 |im (1).

Antenna (Fig. 51): Length 90 )im (1); AR
0.80; lauterborn organs large, extending past
3rd segment.

Head and inoidhparts (Fig. 52): Mentum
with 16 teeth, similar to other members of the
genus. Ventromental plate (Fig. 52) with 40-61
fine striae. Premandible with a conspicuous
brush, 2 apical teeth, and 1 basal shelf-like
tooth. Mandible length 114 |im; seta subden-
talis attenuate, do\\ii-cui"ved at tip, extending
past the basal tooth, similar to that illustrated
by Pinder and Reiss (1983: Fig. 10.60C); sub-
apical tooth heavy, scarcely exceeded in length
by the apical tooth; mola with 1 very weak den-
ticle; seta interna with numerous fine branches,
major branches not discernible. PectcMi epipha-
rxiigis, chaetiilac laterales, ungula, and basal
sclerite similar to that of P. (Trijxxlura) ^ri-
seopunctatus (Malloch) (Soponis and Simpson
1992), but widi 5 denticles in each of the lat-
eral plates of the pecten epiphar\ iigis and 6
chatulae laterales on each side; S 1 and S II
simple, hmbriate. Chaetae 5 on each side, weak-
ly fimbriate. Spinulae 2. l^acinial cliactac of
maxilla 3, the most anterior one hea\ iest, reach-
ing to midline ol head; 2nd about as long but
narrower, and 3rd greath reduced, \la\illar\
palpus slightK' longer than wide, with at least 7
apical sensillae. Dorsal labral sclerites obscured.

Body. Anterior paiapods separate, mostlx
w ith pectinate claws. Procerci each with 6 ter-
minal setae and 2 anterior setae; hfW of pro-
cercus about 1.0. Claws of anal parapod \el-
l(m', simple.

Diagnosis. — This species closely resembles
P. (Tripodura) pterosopilus Townes in vdng fea-
tures but differs from that species in ha\ing
the basal dark spot in cell R5 clearK' separated
from the r-m cross\'ein and lia\ing spots along
the anal margin broader and heaxier (cf Sub-
lette and Sasa 1994: Fig. 181). Male genitalia
anal point is longer and more lanceolate (cf
Sublette and Sasa 1994: Fig. 182) than in P
pterosopilus (Townes 1945: Fig. 32). The geni-
talia of P. (Tripodura) labeculosum (Mitchell) are
more similar to this species (cf Sublette 1960:
Fig. IC), but the wing spots of P. laheeulosuni
are distincti\ el\ different (cf Townes 1945: Rg.
211). Immature stages in this genus are still
inadequately knowTi. Of the known southwest-
ern larvae this species most closely resembles
P. labeculosum in haxing antennal segments
3-5 about equal to segment 2, \entromental
plates finely striate (30-47 striae), head cap-
sule largely pale, and posterior margin of the
ventromental plate not strongly sinuate. Fhis
species differs, howexer, in haxing the 5th
antennal segment minute and scarceK distin-
guishable. The pupa differs from most other
southwestern species in having the anterior
band of shagreen onl\' slightK- greater densit\
than die middle and posterior bands of T 1 l-\'l.
This, coupled with the hea\ \-, somewhat di-
vided, posterolateral spur of T \ III, presents a
unique appearance among the southw-c^stern
Poh/pcdilum.

DiscL ssioN AND Kc:()L()t;v. — The presence
of P. obelos in Grand Ganyon represents the
northernmost occurrence of this recentK de-
scribed Neotropical species. The ri'laled P.
labeculosum and P. pteroso})ilus also ri'presi-nt
|)r()l)al)le Neotropical forms with rangt' exten-
sions into the sonlhwcstern I iiiti'd States.

Disi-Kiiu HON. — Guatemala, .\ri/,ona, New-
Mexico

MatisIUAi. iivwiiNKD. — AZ: Goconino C^o.,
(irand C'anxon National l^ark, Colorado Rixer,
1 S and IV\. rixcr mi 61.0, 6(i3 ni eli'\ ; I 6
and Pc\. I l,e\, ii\n mi l(i(i.O, (vf6 ni ele\.

Poli/pediluiii (Pripodura)
apicatum Tow nes

ruhijiidiliiiu \ rrijiotliird' (ipicdtiim '\o\\\\vs Ui l."i;.)f): t\|)i'
liualih, Las W^as ilol Springs, NM; Hocsi'I iyS.5;25S, rc-
\ iiw ; ( )li\c-i- ft al. 1990:52, cataloi;, clislril)iiti()n.

1998]

GiuM) Canyon CJiiikonom id Taxonomy

137

Diagnosis and disci ssion. — Features of
the male genitalia and the eharaeteristie spot-
ted wing are distineti\i' (el. Townes 1945: Ings.
31, 207).

EcOL(H;Y. — Tills speeics is loiiiul at low
ele\ations in the Southwest and has been eol-
leeted in desert springs.

Distribution. — Ciilifornia to Colorado and
New Mexico; Illinois.

Material IvXaminkd. — AZ: C^oeouino Co.,
Crand ('an>()n National Park, (Colorado Ki\er,

1 S , ri\er mi 164.5, 533 m ele\'; 1 6 , ri\er mi
166.5, 532 m elev.

Trihc Tun tarsiui

(■Iddotdiiytarsii.s iiuirki
Sublette, new species

(Fig. .5.3)

Holotype male. — AZ: Coconino Co.,
Grand Cannon National Park, C-olorado Ri\er,
river mi 174.3, 518 m ele\, UV trap, LES
(CAS).

Coloration: Head, antepronotum, thoracic
vittae, preepisternum, a spot on the pleura,
and postnotiuu blackish brown; humeral, pre-
scutellar, and pleural areas and scutellum Yel-
lowish; legs and abdomen dark.

Head: Antenna widi 13 flagellomeres. Anten-
nal ratio 0.72 (0.60-0.64; 3). Palpal proportions
23:78:78:125 |lm. Eyes reniform; ocular ratio
0.71 (0.64-0.72; 3). Clypeus truncate triangu-
lar, \\ idth at base 0.65 of w idth of antennal
pedicel; with 8 (8-10; 4) setae. Temporal setae
9 (8-9; 4), in a single row, reaching to over
half^vax' to midline of the head.

Tliorax: Antepronotum triangular, evanes-
cent dorsalK. Thoracic chaetota\\ : lateral ante-
pronotals lacking; dorsocentrals 7 (5-6; 4), in a
single row; acrostichials 5 (5—6; 4), partialK in

2 rows; prealars 1(1; 4); supra-alars lacking;
scutellars 2 (2-4; 3), in a single row.

AV//ig: Membrane with sparse macrotrichia
at the tip; 1144.5 ^'i^l'' y'pi">' slightK pro.ximal to
apex of Ml +2- R2-1-3 ^"^^^ ^* 0.65 (0.56-0.65; 4)
of the distance between apex of Rj and R4+5.
\enarum ratio 1.25 (1.27-1.31; 5). Wing length
1.26 (1.18-1.45; 4) mm. Wing vein setae: R 10
(7-10; 4), R4+5 4 (1-5; 4), Mi+2 15 (7-15; 4).

Legs: Foretibial spine length 12 fim; middle
tibial spurs subequal, lengths 10 |im; hind tib-
ial spur lengths 10/8 jim. Pulvilli xestigial. Leg
ratios: P I 1.58 (1.89-1.97; 3); P II 0.53 (0.53-
0.56; 3); P III 0.65 (0.61-0.67; 3). Sensilla chaet-
ica P II 2 (2; 3).

Abdomen: (k'uitalia (Fig. 53). Ninth tergum
with 6 (3-11; 4) setae; ventral anal point setae
extending slightlv beyond middle ot anal point
(Fig. 53, inset). Gc/Gs ratio 1.43 (1.26-1.45; 4).

Diagnosis and discussion. — The medially
concax e inferior \ olsella separates this si^ecies
Ironi all described Nearctic (^.ladotanytar.siis
except C. daviesi Bilyj and C-'. pinnaticornis
BiKj. In those species the anal point spinulae
\\d\v nuiltiple points at the tip with the spinu-
lae and 9th tergum setae distinctK separated
in both size and shape, while C. niarki has
simple tips so that the spinulae grade into the
9th tergum setae.

Paratypes. — AZ: Coconino C>'()., (Colorado
River, Grand Canyon National Park, 1 6 , river
mi 108.5. 663 m elev, 26-XI-91, TCM; 4 S6,
collected w ith the holotype 6 (CAS, USNM).

This species is dedicated to the son of JES,
Dr. J. Mark Sublette, who has devoted many
hours in the field in pursuit of elusive midges.

Ecology. — This species has been collected
in cold-stenothermic conditions in both steep,
narrow, bedrock-constrained and w ider reaches
of the mainstream Colorado Rixer.

Distribution. — This species has been col-
lected only in the lower half of the Colorado
River corridor in Grand Canvon, Arizona.

Mieropseeira sp.

Dl\g\osis and discussion. — A single fe-
male pupal exuY'ium was taken at Lees Feny on
30 December 1990, but the lack of knowledge
on female pupal morphologv' prevented iden-
tification to the species level.

Ecology and distribution. — The most
common southwestern Micropsectra is M. nigri-
pda { Johannsen), which has a very broad eco-
logical tolerance, occurring in a variety of
flowing watei".

Material e.vwiined. — AZ: Coconino Co.,
Grand Canvon National Park, Colorado R, 1 9
Pex, river mile 0.0, 950 m elev, 30-XII-9().

Eheotamjiar.sus ha))uitUH
Sublette and Sasa

RJieutanytar.'iU.s hamatm Sublette and Sasa 1994:52; t>pe
locality, Rincon, Guatemala.

Diagnosis and discussion. — The genitalia
of the males available are in rather poor condi-
tion; however, the stronglv hooked gonostvlus,
short medial volsellus, and distinctivelv' shaped
superior volsellus are clearly visible (cf.

138

Great Basin Naturalist

[Volume 58

1m«. .->!. Cruulupn.s ^Cnn>U,,n,..! hiiiuu. scuhumi; cUrtrnn ininoKniplis (dockwisc Iroin top Irt'tl: Uil malr, luM.l ami tlu.na
(dorsolak-ial view); (h) pupa, tc-iKiini ill (laffial view); (c) male, jic-uitalia; (d) pupa, ivcunvd liooks of ti-ruuin II; (f) inali-,
claws and associated structurt-s; (i) male, ^ouostylus (ventral); («) gonost\lus (medial); (h) ,u<)uost> lus (lateral).

1998]

Grand Canyon (.'iiiHoNoMin Taxonomy

139

Fig. 55. Cricotopus (Cricotnpu.s) blinni, scanning electron micrograph.s (clockwise from top left). Lana: (a) mandible
(3-piece collage); (b) head (ventral view); (c) anterior parapods; (d) ma\illar>' palpus apex; (e) maxilla.

140

Great Basin Natl fl\list

[\blunie 5(S

Fig. 56. Cric()to))its (Cricotopus) {ilolnstnUis. scaiiiiiim cU'ctron iiiicroiiraphs (clockwise Ikhii top left). Male; (a) lli()r;L\
(dorsolateral \ie\\). Pupa: (h) ter,u;a 1\'-VI (3-piece coilatie); (c) reciir\e(l hooks oltermiui II: (ill teri^iuu II.

Sublette and Sasa 1994: Fii^. 1S8), thus pnn id-
ing a positive identification.

Ec()L(x;y a.nd DiSTHiBUTioN. — In Arizona
this species has been collected in cold-steno-
thennic conditions in the Colorado Ki\( i just
below the Pari a l{i\(r.

Material i;,\A\II\i:I). — .\Z: Coconino Co..
Grand Canyon .National l^irk, (.'olorado l\i\(i,
4 (5, river mi 133.5, 610 \\\ ele\.

Sl\i\i \iu

The chirononiid launa ol the (ioloiado Www
in (irand CauNon is depauperate in loinpari-
son with other North .\nii'rican rixers. Onr
sample of nearh loOO lai\al, pnjxil, and adnll
chironomid specimens included 3S specii'S in
2.) <j;enei"a and I sublamilics. Tiie launa was
dominatctl 1)\ 23 specii's in llii' sublamiK

1998]

C;ha\i) (:\\^()\ CiiiKoxoMin Taxonomy

141

Fig. 57. Cricotopti.s iCrictitopti.si Iwrnnaiuu, scaaiiiiig electron inicrograph.s (clockwise trom top lelt). Male: (a) genitalia;
(b-d) gonost) Ills, positional variation.

Orthocladiinae, with Cricotopus annulator >
C. <ilobistyhi.s > Eiikiejferiella claripennis >
Otihodadhis rivicola > Tvetenia vitmcies. Chi-
ronomiis spp. (subfamiK- Chironominae) were
regularly encountered in low densities in pool

liabitats floored with fine sediment. Twelve chi-
loiiomine species were collected overall. Pro-
cladius hcUus, Paracladhis conversus, Chirono-
inus decoriis, C. sp. 1, and C. sp. 2 were col-
lected onlv in the headwaters of Lake Mead.

142

Great Basin Naturalist

[Volume 58

Stevens et al. (1998) present a synthesis and
summary' of the Colorado River chironomid
assemblage from the data presented here.

Acknowledgments

This project was partial!) funded b\' the
Bureau of Reclamation Glen Can\'on Enxiron-
mental Studies (GCES) Program and the Grand
Canyon Monitoring and Research Center
(GCMRC), and b\' National Park Senice Con-
tract CA-8()()9-8-'0002 through Northern Ari-
zona University, Department of Biological Sci-
ences, Flagstaff, Arizona. We thank David
Wegner and his staff at GCES for logistical
support, and L. David Garrett (GCMRC) for
support in publication. Dean W. Blinn provided
project support and oversight. Jeanette Mac-
calley, Gaye Oberlin, and Teresa Yates prepared
the specimens reported herein. Man Sublette
provided indispensable assistance organizing
and preparing the manuscript. Of the electron
micrographs presented, Figure 55a was pre-
pared b\' Deseree Padilla, 54b b\' Jill Decker,
and 54c, d,e by Allen Wood, all students in an
electron microscopy course taught by JES at
the University of Southern Colorado; all other
micrographs were done by JES, who grate-
fully acknowledges university access to the
scanning electron microscope for this project.
We thank Dr. M.W Boesel, Miami University,
O.xford, Ohio, for the privilege of examining
paratypes of Cricotopiis olivetiis Boesel. Val
Saylor and Renee Davis kindly provided addi-
tional graphics and editorial assistance. We
thank several anon) nious re\ iewers for valued
editorial criticism.

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/ErriRsiEDl', J.W. 18.38. Dipterologis Scandiiia\ae. Sec-
tion .): Dipli'ia. 477-8(i8.

RiTciicd2<).\pril 1997
Accepted 5 Aii'iiixt 1997

Croat Basin Xafiiralist 58(2), © 199S, pp. 147-155

CHIRONOMIDAE (DIPTERA) OF THE COLORADO RIVER,

GRAND CANYON, ARIZONA, USA,

II: FACTORS INFLUENCING DLSTRIBUTION

l.awR'iifc E. Stcxens', James E. Sublette-, and Joseph P Shannon'^

Abstract. — BiogeoRiaphic, flow regulation (water clarit>' and temperature), and temporal influences affect the com-
position of the chironoinid midge assemblage in the Colorado Ri\er between Clen Canyon Dam and Lake Mead. This
assemblage is dominated by ennecions N'earctic and Holarctic orthocladine ta\a (23 of 38 total species, total weighted
relati\e abundance [W'KA] = 0.972) and includes a minor Neotropical component. Chironomid species richness
increases o\er distance downstream from the dam, and dominance shifts across 3 turbidity segments. Ele\en species
occur in the cold-stenothermic clear\vater (CW) segment between the dam and the 1st perennial tributar\' (the Paria
Ri\er, 26 km from the dam). Chironomid di\ersit\' increases from 18 to 24 species in the variably turbid (VT) and usually
turbid (UT) segments dowiistream, respecti\el\'. Total Cricotopus spp. WRA is negati\ely correlated with distance (tur-
bidit\ ). while total CMiironominac \\'R.V shows the opposite patteiTi. In contrast to chirononud di\ersity, species density
decreases from 0.42 species/km in the (S.W segment to 0.19 and 0.08 species/km in the \T and UT segments, respec-
tiveK. Seasonal dominance shifts slightb from orthocladine Eiikicjferiella spp. in winter (WRA = 0.101) to Cricotopus
spp. (\\'R.-\ = 0.165) in sununer. Total \\\\.\ is lowest in spring (0.191j. The assemblage is depauperate compared with
other western ri\ers and has changed o\er post-dain time.

Key words: hiodiiersity, hiogeo<irapliii. C'liiroiiontidtie, Colorado River commimitij, flow re'gulation. Glen Canyon
Dam. Grand Canyon, serial discontinuity concept.

Chironoinid nudges phiy important roles in
both aquatie and terrestrial food webs in river
ecos\ stems. The Colorado Ri\er is one of the
most thorougliK' regulated Ameriean rivers
(Hirsch et al. 1990), and chironomids are abun-
dant or dominant taxa in man>' segments (Pear-
son 1967, Rader and Ward 1988, Wolz and
Shiozawa 1995, Stexens et al. 1997). VirtualK
no pre-impoundment mainstream benthie data
were collected (Blinn and Cole 1991). Follow-
ing completion of Clen Canyon Dam in 1963,
Stone and Rathbun (1967 unpublished) docu-
mented rapid changes in benthie macrophyte
distribution at Lees Feny, but reported the
presence of only a single group of chironomids:
ooze-dwelling "bloodworms" (Chironominae,
probably Chironnmus spp.). Sublette et al.
(1998) identify- 38 species of chironomids from
the post-dam Colorado River in Clen and
Crand can>ons and discuss their autecology.
These riverine Chironomidae link aquatic and
ten-estrial trophic components in Crand Can-
yon (Angradi 1994, Angradi and Kubl>' 1994a,
1994b, Blinn et al. 1995).

The Colorado Rixer chironomid assemblage
is influenced by biogeography (Sublette et al.
1998) as well as temporal and environmental
factors, including flow regulation. However,
detailed distributional data on individual chi-
ronomid species are rare, and phenologN' is well
documented for rather few species. Hofnecht
(1981) attributed low macroinvertebrate abun-
dance in Crand Canyon tributary mouths to
cold-stenothermic and fluctuating mainstream
flows. Stevens et al. (1997) report that riffle
and pool habitats in the clearwater segment
immediately downstream from the dam support
equally high densities of chironomid lanae in
dense beds of the benthie alga Cladophora
glomerata. In contrast, cobble bars in more tur-
bid downstream segments support substan-
tially greater chironomid abundance than do
mainstream pool habitats. Chironomid species
richness is low do\\ii stream from Clen Canyon
Dam (Sublette et al. 1998), but other factors
influencing di\'ersit\', such as seasonal phenol-
og)' and impoundment imf)acts on water clar-
ity, have not been analyzed.

't;rancl Cain on Monitoring and Research Center. Bo,\ 22459, Flagstaff, .\Z 86002-24,59.

23550 N. Winslow Dr. Tucson, AZ 85750.

■'Department of Biological Sciences, Northern Arizona Uni\ersit\', Flagstaff. .\Z 86011.

147

148

Great Basin Naturalist

[Xblume 58

la tliis paper we s\ nthesize taxonoiiiic and
ecological data of Sublette et al. (1998) to
descrilie factors influencing the chironomid
assenililage of the Colorado River between
Glen Canyon Dam and Lake Mead. We use
data fioni presen ed pharate and adult chirono-
mid specimens collected from 1974 through
1991 to describe biogeography, spatial and
temporal distriljution, and influences of flow
regulation on this assemblage. Our results pro-
\'ide the first quantitative description of the chi-
ronomid assemblage in this portion of the Col-
orado River and establisli a baseline for moni-
toring future change in these assemblages.

Methods and Materials
Study Area

The channel of the Colorado River between
Glen Canyon Dam and Lake Mead is con-
strained b\' talus slopes and bedrock. The river
descends from an elevation of 955 m to 370 m
over its 472-km-long course through Sonoran
and Mohave Desert tenain (Wairen et al. 1982).
By convention, distances along the river are
measured from Lees Ferry (river km and mi 0,
25 km downstream from the dam; Sublette et
al. 1998: Fig. 1). The pre-dam mean daily flow
ranged from <1()() to >25()() mVs (Howard
and Dolan 1981), with a spiing snowmelt peak
flow, erratic summer flows, and low winter
flows. Pre-impoundment flows transported
more than 60 x 10^^ mt/yr of inorganic sedi-
ment (Andrews 1991), and undoubtedly much
organic drift. Water temperatures ranged from
0°C in winter to >29.4°C at Lees Ferry in
summer before completion of the dam. Tiie
ri\er channel is constricted In debris fans at
the confluences of >500 mostly eplu ineral
tributaries. Runs, riffles or rapids, pools, and
back'\\aters are primaiy rixer habitats, and their
distribution varies through 13 bedrock-defined
reaches (Schmidt and Graf 1990, Stexens et al.
1995, 1997).

Completion of (ilen Canyon Dam in 19(i3
reduced ellects of regional climate on the Col-
orado River and altered chironomid habilat
availability. The post-impoundment Inclrograpli
has been characterized 1)\ large honrb, but rcl-
ati\cl\ minor seasonal, flow xariabilitx (I low aid
and Dolan 1981, U.S. Bureau ol Kcilainalion
1995). Between 1963 and 1991. lionrK flow
N'ariation for Indroelectric |)ow('r prodnelion
created daiK "tides of >3 m that inundated or

desiccated shoreline habitats (Blinn et al. 1995).
Seasonal thermal variability has been replaced
by cold-stenothermic (hxpolimnetic) flow re-
leases (8-9°C) at Lees Ferrx, and water tem-
perature increases to only 17°C at Diamond
Creek (km 364, mi 226) in summer (Stevens et
al. 1997). Stabilized flows permit widespread
establishment of atjuatic, wetland, and riparian
\'egetation (Stone and Rathbun 1967 unpub-
lished. Turner and Karpiscak 1980, Johnson
1991, Stevens et al. 1995), which serxe as chi-
ronomid habitat. Sediment retention in Lake
Powell increases water clarity in lower Glen
Can) on; however, the Paria River (km 1, mi 0.7),
Little Colorado River (km 98, mi 61), and other
tributaries supply e.xceptionalK' concentrated
suspended sediment loads (Andrews 1991, Graf
et al. 1991). These tributaries create 3 turbidity-
segments: the 26-km-long cleanvater (CW)
segment from the dam to the Paria Ri\ er con-
fluence, the variabK turbid (\T) segment from
the Paria River and Little Colorado River
mouth, and the usually turbid (UT) segment
(km 98 to km 386, mile 240). In addition,
upper Lake Mead (ULM) constitutes a usualb
turbid, lacustrine segment from km 386 to km
442 (mi 278).

Field and AnaK tical Methods

We collected adult and pharate afjuatic
Diptera throughout the year in 1976-77 and
1989-92 1)\' sweep-netting I'iparian xegetation
(particular!)- Salix i'.\i<i,U(i, T(i)narix raiiiosis.sima,
and Baccharis spp.), white- and L'\' light-trap-
ping, dip-netting, and larval rearing from ben-
thic spot and quantitative samples (Sublette et
al. 1998). Ta.xonomic determinations and de-
scriptions follow Sublette et al. (1998), which
also includes additional information on collec-
tion methods, locations of sp(>cimens, and la\-
ononi).

We conducted spatial and seasonal anaKses
using data from 1018 slidc--inounted pharate
and adnll spi'tiniciis Ironi 212 saini)les col-
Ii'cted throughout the stud) area b) Stexens
(1976) from 1974 to 1976, and from 1989
through 1992. Up to 10 spciinu'ns ol \isuall\
apparent species Iroui each sample were' slidc-
nionnled ioi' identilitation. Twcnt) samples
wcri' eolleeled liom the CW segment, 76 from
the \T segment. 1 13 from llu' UT segment, and
3 Ironi the UL\1 scgnieiit. Beeause lew sam-
ples were eolleeled in tlu" last si-gment, wc
pooled UL.\1 data with UT data. We sampled

1998]

Grand Canyon (;iiir()N()\iii) Disikiiu i ion

149

C^liironoinichu- throiiuliout flic \(\ir. with 54
samples coIKctc'cI in wiiitci- ( l)(.'ccMiil)t'r-lvI)-
niaiA), irl in spriiiii (Maicli-Ma\ ), 47 in suiii-
iiier (June-August), and 49 in autunni (Scp-
tt'inber-November).

B\ weiuhtinti the relati\e abundance of each
species in relation to the number ot samples
collected in each turbidit\ segment, we stan-
dardized spatial distribution ot adult chirono-
mids. Species densit\' was calculated b\ di\ id-
iiig tlu' munber ol species in a turbiditx seg-
ment b\ segment length (km). Seasonal varia-
tion was standaiclized by weighting each
species relatixe abundance b\ the numbi'r ol
collections made each season.

Results and Discussion
Composition

The chironomid fauna of the Colorado River
in Grand Canyon is depauperate in compaii-
son with other western ri\'ers (e.g., Sublette
and Sublette 1979, Wolz and Shiozawa 1995,
Spindler 1996). Our collections include 3(S
species in 23 genera and 4 subfamilies (Table 1).
The fauna is dominated by the Orthocladiinae
(23 species), with 5 abundant species: Cricoto-
piis (iniiiilator > Cricotopus ^lolyistyhis > Eii-
kicffcru'IIa claripcium > OiiJwcIadius livicohi
> Tvctcnia vitracies. The fauna includes 12
Chironominae species, with Chirononuis spp.
regularK found in low densities in pool and
back"\\ater habitats floored with fine sand or
silt, and w ith Proclddiii.s hclliis. Paradadnts con-
vcrsu.s. C'liiroiiofiui.s decorit.''i, C. sp. 1, and C. sp.
2 collected onl\ in the ULM segment.

Spindler (1996) reports at least 43 chirono-
mid taxa in 38 genera from 10 Grand (>an\()n
tiibutar\ streams, adding 20 genera to our list,
for a total ol 43 genera in Grand Canyon. Thus,
more chironomid species ma\ exist in tribu-
tan streams than in the mainstream Colorado
Ri\er. Cow]e>" (1995 unpublished) reports 172
chironomid species or taxa in the highly regu-
lated Rio Grande in New Mexico, 4.5 times as
many species as we encountered in the Col-
orado River mainstream.

Biogeography

Nine of the 38 species collected in the main-
stream Colorado Rixer are Holarctic in distribu-
tion and are madicolous or aufwuchs feeders
(Sublette et al. 1998). All are Orthocladiinae,
and the other orthocladines in diis s\ stem also

piobabK share this feeding strateg\'. The Ortho-
cladiinae are primarily cool- or coldwater tiuxa,
and their dominance in the (^olorado River is
not surprising because the river is now a cold-
stenothermic stream, and because proximitx to
cold, high-ele\ation habitats pnnides a regional
species pool ol potential colonists. In contrast,
the subfamily Chironominae, which largely con-
sists of warmwater species, is represented by
low densities of Chirononms utahensis and C.
decorum in fine-grained habitats. A small Neo-
tropical component is rei:)resented by Pohj-
pc'diluin ohelos and Rhcotani/farsiis iunnatiis,
which pre\iousl\ had been reported onK- from
Ckiatemala (Sublette and Sasa 1994).

The depauperate condition of the Grand
Canyon midge fauna may be explained par-
tially by biogeographic constraints. Ecological
isolation w ithin this large. can\ on-bound, desert
river ma\' ha\e restricted pre-impoundment
chironomid colonization. Colonization may have
been restricted liy the distance from source
areas and by large annual ranges of water and
air temperatures. Also, the combination of fre-
quent large floods and high suspended and
bed-transported sediment loads may have re-
duced pre-impoundment ec(^logical hetero-
geneity", and therefore di\ersit\. Cofhnan (1989)
reviewed chironomid diversity in 152 stream
studies, concluding that stream size and bio-
geographic potential, as well as ecological het-
erogeneit\, altitude, and latitude, influence
chironomid di\ersit\. He reported the greatest
chironomid di\ ersit\ in medium-sized streams.
Thus, the large, isolated, flood-prone, season-
ally warm pre-impoundment Colorado Ri\er
simply may not have supported man\ chirono-
mid species. Polhemus and Polhemus (1976)
similarly attribute the depauperate condition
of the a(|uatic and semiaciuatic Hemiptera
fauna in Grand Cannon to l)iogeographic isola-
tion; howe\er, this argument may not appl\ as
strongly to the Chironomidae because of adult
dispersal as "aerial plankton.

Spatial Distribution Within
the Stud\ Area

The chironomid assemblage changes over
distance from Glen Canyon Dam, through
increasingly more turbid segments (Table 1).
The CW segment supports the highest reach
total weighted relative abundance (WRA =
0.471). The C\\' assemblage is strongly domi-
nated by Orthocladiinae (0.468), particularly

150

Ghkat Basin Naturalist

[Volume 58

Table 1. Sample-weighted relative abuiulaiice of adult Grand Canyon C.'liirononiidae in 3 tnrhidit\ sejinients of tlie
Colorado River downstream from Glen CanNon Dam.

TurbiditN Segments

Varial)l\

UsualK

Clearwater

turbid

turbid

Total

Taxa

in = 20)

in = 76)

(u = 116)

(n =212)

Tanypodinae

Procladiiis hellus

0.000

0.000

0.001

0.001

DiAMESINAE

Diamesia heteropus

0.000

0.001

0.000

0.001

Orthoci^\diinae

Cardiocladius platypus

0.003

0.002

0.003

0.007

Cricotopii.s anmdalor

0.173

0.087

0.044

0..303

Cricutopii.s hliiini

0.000

0.000

0.003

0.003

Cricotupus globistyliis

0.181

0.003

0.001

0.185

Cricotopus hcrnnanni

0.000

0.005

0.001

0.006

Crtcotopii.s infuscatus

O.OOO

0.000

0.006

0.006

Cricotopus trifac.sia

0.003

0.008

0.012

0.023

Undet. Cricotopus sp.

0.000

0.001

0.001

0.001

Subtotal Cricotopus spp.

0.357

0.103

0.067

0.527

Eudactylocladius duhitatus

0.000

0.000

0.000

0.000

EukicjfcricUa claripennis

0.038

0.039

0.060

0.137

Eukicffcriclla cocndescens

0.009

0.004

0.006

0.018

Eiikieffcriclla ilklcye^isis

0.012

0.028

0.016

0.055

Undet. Eukicffcriclla .sp.

0.000

0.002

0.009

0.011

Subtotal Eukicfferiella. spp.

0.0.59

0.073

0.090

0.221

Undet. Limnophycs sp.

0,000

0.000

0.001

0.001

Mctriocncituis stciensi

0.000

0.002

0.000

0.002

Orthocladius jri^idus

0.000

0.000

0.000

0.000

Orthocladius lutipcs

0.000

0.001

0.000

0.001

Orthocladius inallochi

0.000

0.000

0.001

0.001

Orthocladius rivicola

0.032

0.049

0.033

0.114

Undet. Otiltocladius sp.

0.000

0.001

0.002

0.003

Subtotal Orthocladius spp.

0.032

0.051

0.035

0.118

Paracladius coiivcrsus

0.000

0.000

0.001

0.001

Parakicjjcriclla suhatcrriiiia

0.000

0.000

0.002

0.002

Paramctriocncmus luiidheckii

O.OOO

0.000

0.001

0.001

Paraphacnocladius cxa^itaiis

0.000

0.001

0.000

0.001

Pscudostnittid iianscni

0.003

0.000

0.000

0.003

Undet. Pseudosiiiittia sp.

0.000

0.000

0.000

0.001

Tvetenia vitracies

0.015

0.042

0.0.32

0.089

Total Orthotladiinae

0.468

0.274

0.2.30

0.972

Chihonominae

Chironomini

Apcdiliini suhcinctuiH

0.000

0.001

0.000

0.001

Chironoinus deconi.s

O.OOO

0.000

0.003

0.003

Chironomus utahcnsi.s

0.003

0.002

0.000

0.004

ChironotnuH sp. 1

O.OOO

0.000

0.001

O.OOI

Chironomus sp. 2

0.000

0.000

0.001

0.001

Cyphonclla nibhcra

0.000

0.000

0.002

0.002

Phacnospcctra projusa

0.000

0.000

0.001

0.002

Polypcdiliiiit apicatuin

0.000

0.01)0

0.001

0.001

Polypcdiluiii ohclos

0.000

0.000

().()()2

0.004

Undet. Poliipcilituin sp.

0.000

0.000

OOOl

0.001

Tanytarsini

Clatlotaity tarsus inarki

O.OOO

0.000

0.0()(i

0.006

Rhcotanytarsus hauiutus

0.000

0.000

o.oo:]

0.00.3

Undet. Micropscctra sp.

0.000

0.000

0.000

0.000

Total (^liironominae

O.OO.'i

0.006

O.Ol.S

0.027

Grand Total

0.171

().2S1

0.24S

1.000

Total Species Hich.ne.s.s

11

IS

24

3S

Species Densih' (specie.s/km)

0.42

0.19

0.08

1998]

(;KA\I) (;\\Y()\ (-'IIIHONOMID DiS TKIIU I l()\

151

Chcotopti.s (ycMiiis total W'HA = 0.357), witli
C. ^lohistyliis (O.ISI) and C-'. awudator (0.173)
most abundant. EukiejfericUa spp. (tfcniis tola!
WRA = ().()59), particularh- /•:. clariinimis
(().()3(S), and 8 other species are suhdoniinant
in the CM sei:;nient. The ri\er iloor substrata
in the C'W segment has changed from primar-
ily sand to primariK' cobble in post-dam time
I Howard and Dolan 1981). Benthie cobbles
lia\e been coloni/ed by Clddoplioid ^loincrata,
a filamentous green alga that supports abun-
dant epiph\tic diatoms on which chironomid
lanai' leed'dlardwick et al. 1992, Blinn et al.
199.5), and more recentl) b\ additional macro-
plnte tiL\a.

Downstream Irom the eonlluence ol tlu'
small but extreme!) turl)id Paria Ki\ er the chi-
ronomid assemblage undergoes a 3.5-fbld re-
duction in total WRA of Cricotopus spp., with
low-densit\" co-dominance by C. anmdator,
EukiejfericUa chiiipcnnis, Orthocladiits rivicola,
and Tvetcnid vitraeies (Table 1). Low chirono-
mid standing stock biomass (Stevens et al.
1997), low WRA values (<().()61), and contin-
ued co-dominance of these species (except
Tveteuia vitraeies) also characterize the UT seg-
ment in lower Grand Canyon. Chironomid
diversity increases from the CW (11 species)
to the VT segment (18 species) to the UT (24
species); however, species densit\' decreases
from 0.43 spp. /km to 0.19 spp./km and 0.08
spp./km through these turbidity segments,
respecti\'el\'.

Similaritx with Other
Western Rivers

Similarit) between the Grand (>an\()n chi-
ronomid assemblage and that in other portions
of the Colorado Ri\er or in other western
rixers is negatively related to distance from
our study area. Eighteen of 38 chironomid
genera reported b\' Spindler (1996) in Grand
Can\()n tributaries also occur in the Colorado
Ri\er mainstream; however, additional sam-
pling of other tributaries, seeps and springs,
and can>()n rim wedands is needed to provide
a more complete understanding of chironomid
diversity in Grand Canyon.

The post-impoundment Colorado River in
Grand Canyon supports habitats and chirono-
mid species that also occur in die upper and
middle Green Rixer, 600 km upstream. Wolz
and Shiozawa (1995) report 19 genera of Chi-
ronomidae in Oura\' National Wildlife Refuge,

Utah, in low-\'(>locity enviromnents, including
C^hir()n())niis, (Cricotopus, Cryptocliiroiunnus,
I\>lype(liluin, Procladius, Tanypus, and Tany-
larsus. Chironomid density there ranges up to
31,125/m- in river backwaters, an order of
magnitude greater than that in the mainstream.
The Grand Canyon portion of the Colorado
Ri\ er also contains numerous backwaters; how-
ever, steep gradients and swift currents limit
fine-sediment deposition. C^onseciuentK; chi-
lonomid densities (primarily Chironomus spp.)
in contemporary Grand Canyon back-waters
are t\picall\' <l()()()/m2 (Stevens unpublished
data), ('hironomids in the Colorado Ri\er in
Cirand Can\'on are often more concentrated in
cobble bar habitats, which are relatively rare
on the sand-floored Green River. Habitat avail-
ability and biogeograhic constraints are proba-
bly responsible for assemblage variation be-
tween the 2 study areas.

Cowley (1995 unpublished) describes chiron-
omid assemblages in the Rio Grande in New
Mexico using Ward's (1963) clustering algo-
rithm. He reports a total of 172 species that
can be categorized into 3 distinct clusters. The
1st cluster includes 19 "widespread species,"
of which 8 also occur in Grand Canyon. His
2nd cluster comprises cold, cleanwater species
and shares 9 species in common with the Grand
Canyon fauna. His 3rd cluster includes species
of lower ele\'ations and shares 7 species in
common with the Grand Canyon fauna. Five of
the remaining 13 species from Grand Canyon
could not be identified to species level be-
cause of poor preservation but probably also
occur in New Mexico as members of the 3rd
cluster. Thus, at least 24 (14%) of the Rio
Grande chironomids co-occur on the Colorado
River mainstream, a relati\el\ small amoimt of
faunal overlap when compared to the compo-
sitional overlap at other locations within the
Colorado Rixer basin.

Flow Regulation Impacts

The serial discontinuity' concept (SDC; Ward
and Stanford 1983) predicts that macroinver-
tebrate diversity' decreases following impound-
ment, but increases with distance downstream
from large dams on large rivers. The depauper-
ate midge diversity in Grand Canyon generally
supports the predictions of that model and re-
flects impoundment influences of cold-steno-
thermic release temperatures and fluctuating
flows (Blinn et al. 1995). Water temperature

152

Great Basin Naturalist

[\blume 58

during prepupal and pupal development influ-
ences chironomid emergence, at least for arctic
lentic chironomids (Danks and Oliver 1972,
Welch 1973, Butler 1980), and seasonal warm-
ing cues lanal de\ elopment (Ward and Stanford
1982). .'Vithough the CW segment supports ex-
tremely high benthic standing biomass, onl\
those species capable of toleiating cold-steno-
thermic conditions can persist there. Taxa we
report there are primarily euiyecious Nearctic
or Holarctic Orthocladiinae, with relatively
large body sizes (e.g., Cricotopus spp.). The
great abundance but low diversit\ of chirono-
mid species in the CW segment reflects the
large standing stock biomass of epiphytic algae
and relatively high productivity (Blinn et al.
1995, Stevens et al. 1997). The negative cor-
relation between chironomid species density
(as the number of species/km) and distance
downstream does not follow SDC predictions,
suggesting that the SDC may be refined by
additional stud)' of species/area biogeographic
influences.

Potential niche diversity (as the range of
a\ ailable t\pes of niches) increases downstream
in Cxrand Canyon through increased seasonal
variation in water temperature, increased size
and abundance of back'waters in wide reaches,
variation in benthic algal composition, increased
organic drift from tributaries and allocthonous
sources, and increased variabilit>' of other eco-
logical gradients (Schmidt and Graf 1990, Shan-
non et al. 1996). Dominance shifts from a lower
diversity of larger-bodied Cricotopus spp. in
the upstream cleanvater segment to an assem-
blage dominated by smaller-bodied madicolous
taxa (e.g., EiikiejferieUa spp.), with lower abim-
dance and species density in downstream
reaches. This pattern is at least partially attiib-
utable to turbidity (distance)-related reduction
in ac^uatic macrophyte standing biomass, which
pro\ ides abundant food and habitat upstream.
Dam impacts on temperature limit inxfitebrale
diversity, while water claiitx limits benthic
standing biomass in this system.

(^owlex (1995 unpublished) cxannnes [\\v
similaritx of chironomid assemblages in regu-
lated and unregulated reaches oi the Rio (irande
in New Mexico, reporting 5 groups ol sites if
clusters and 1 outlier site). His least perturbed
(outlier) site on the Chama Hi\cr suppoits 7(i
species, of which 22 occin- oiiK al thai site.
One group of sites on the C^hama liiwi con-
tains 2 stations downstream from dams. Thosi-

sites ha\t' higli mean diversity (41 species/site)
but, on average, only 4 unique species per site.
A 2nd cluster, representing moderate to low
water quality, has a mean of only 25 species
with a mean of only 2 unicjue species per site.
The di\eisit\' pattern in this cluster reseml)les
that in oui" study area; however, Colorado River
water quality' is relatively high. In contrast to
our study, Cowley reports that Chama Ri\er
chironomid diversity is negativcK' correlated
with distance downstream from Abiquiu Dam,
with highest midge diversity at the coldest sta-
tion just downstream from the dam.

Sublette and Sublette (1979) compare the
Chironomidae from regulated and unregu-
lated sites on the Na\ajo Ri\ er abo\e Navajo
Dam and on the San Juan River at Farming-
ton, New Mexico, about 65 km downstream
from the dam. They report 67 species at the
above-dam site and 56 below the dam, just
downstream from the Animas Ri\ er confluence
at Farmington, New Mexico. The abo\e-dam
site is comparable to Cowley's least perturbed
site on the Chama River, while the assemblage
below the dam resembles his 1st cluster on
the Chama Ri\'er. The influence of that rela-
tively large tributary' restores water tempera-
ture variability and may explain the similarit\'
of chironomid di\ersit\' abo\ e and below the
impoundment. No tributan entering the Grand
Canyon portion of the Colorado River is large
enough to restore mainstream temperature,
and flow regulation impacts on temperatine
persist throughout flic entiit' study area (Stevens
et al. 1997).

Hourly flow fluctuations in (iiand Canxon
affect chironomid di\ersit\ b\ regulaiK inun-
dating or desiccating large portions ol tlu'
shoreline (Blinn et al. 1995). We observed, but
did not (juantify, rapid emergence of Cricoto-
pus and other chironomids from Cladophora
^loincnitd beds exposetl 1)\ fluctuating flows.

Temi^oral \arialion

The chironomid assemblage in Cirand C-an-
\ on changes onl\ slighlK between seasons but
has shifted o\er post-dam time (Table 2). (-hi-
ronomid dixcrsit) increases from 17 spi'cies in
w inler and spring lo 22 and 21 species in sum-
mer and autumn, i-cspeeti\i'l\. Spring, summer,
and aufunm assemblagi's are dominated b>
('ricolopiis spp. (genus WRA = 0.076, 0.165,
and 0.114, respectixcK), particularK C-. aniiii-
Idlor \\ inter dominance shifts to EukicfjcriclUi

1998]

CkAM) C>A.\Y()\ C'lllKONOMin DiSTHlBL HON

153

Table 2. Seasonal sample-vveiglited relati\ t^ aljundance ol adult Grand Canyon Cliirononiidae downstream from Cilen
Canyon Dam: winter (December-Februar\ ), spring (March-May), summer (June-August), autumn (September-
No\emb('r).

Se

ason

Winter

Spring

SunniiiT

.\utuinn

Total

Ikxa

(»i = 54)

';i = 62 1

in = 47)

in = 49)

in = 212)

Twvi'oDiwi:

rroclddiiis hcllti.s

0.000

0.000

0.001

0.000

0,001

Di.witsiNAt;

Diaiiu'sid hctcropu.s

0.000

0.000

0.000

0.001

0.001

()ktiioc:l.\diinak

Cardiocladius pldtypm

0.003

().()()3

0,001

0.001

0.008

Cricotopu.s (innulator

0.013

0.049

0.114

0.0S6

0.262

Cricotopiis hlinni

0.001

().()()()

0.001

0.003

0.005

CricotoiHLs ^lohi.stylti^

0.011

0.017

0.030

0.009

0.067

Cricotopu.s herniuiniii

0.000

().()()7

0.000

0.000

0.007

Cricotoptis iiijuscatiis

0.003

0.001

0.006

0.002

0.011

Cricotopus trifacsia

0.006

0.003

0.014

0.014

0.036

Undet. Crkotopu.'i sp.

0.000

0.001

0.001

0.000

0.002

Subtotal Cricotopus spp.

0.034

0.076

0.165

0.114

0.389

Euclactylocladius dtihitdtus

0.000

0.000

0.000

0.000

0.000

Eiikicffcriclla claripcnnis

0.058

0.041

0.021

0.055

0.175

Eiihicjfcriclla coerulcscens

O.OOS

0.005

0.002

0.003

0.018

Eiikicjfcriella ilklcyensis

0.023

0.021

0.019

0.005

0.067

Undet. EiikiefferieUa sp.

0.012

0.003

0.003

0.002

0.020

Subtotal EtikiefferieUii spp.

0.101

0.070

0.045

0.065

0.280

Undet. IJmnophyes sp.

0.001

0.000

0.000

0.000

0.001

Metriocncinm stecensi

0.000

0,001

0.001

0.000

0.002

Orthocladius frinkhis

0.000

0.000

0.000

0.000

0.000

Oiiltoclcidiiis lutipcs

0.000

0,000

0.001

0.000

0.001

Orthodadiu.s mallochi

0.000

0,001

0.000

0.000

0.001

OrthocUidius rkicola

0.071

0,017

0.034

0.015

0.136

Undet. OrthocUidius sp.

0.004

0.001

0.000

0.000

0.005

Subtotal Orthoclcidius spp.

0.075

0.018

0.035

0.015

0.143

Paracladiu.s con icrsu.s

0.000

0.000

0.000

0.002

0.002

PurukicjfcrwUa sul)atcrrim(i

0.001

0.001

0.000

0.001

0.003

Parumctriocucmu-s lundheckii

0.000

0.000

0.001

0.000

0.001

Paraphacnocladius exagitans

0.000

0.000

0.000

0.001

0.001

Pscudosinittia iianscni

0.000

0.001

0.000

0.000

0.001

Undet. Pscudosinittia sp.

0.000

0.000

0.001

0.000

0.001

Tretenia vitracics

0.033

0.021

0.007

0.060

0.120

Total Orthocladiiiiae

0.248

0.190

0.256

0.259

0.953

ClIII«)\C)\IINAK

Chirononiiiii

Apcdiluin sulHiiutiiin

0.000

u.ouu

o.uoo

0,001

0.001

Chiroiioinus dccorus

0.000

0.001

0.002

0.002

0.005

Cli iroiiom us utalicnsis

0.001

0.000

0.002

0.000

0.003

Chinmomus sp. 1

0.000

0.000

0.000

0.002

0.002

Chinmomus sp. 2

0.000

0.000

0.000

0.001

0.001

CyphoncUa gihbcra

0.002

0.000

0.001

0.000

0.003

Pliacnospcctra profusa

0.003

0.000

0,000

0.000

0.003

Polypcdiluin apicatuin

0.000

0.000

0,001

0.001

0.002

Polypcdiluin ohclos

0.006

0.000

0.000

0.000

0.006

Undet. Polypedihtm sp.

0.001

0.000

0.001

0.000

0.002

Tan\tarsiiii

Cladotanytarsus inarki

().()()()

0.000

0.002

0.009

0.012

Undet. Micropscctra sp.

0.000

0.000

0.000

0.000

0.000

Rlieotanytarsus hamatus

0.000

0.000

0.006

0.000

0.006

Total Chironominae

0.012

0.001

0.015

0.017

0.045

GfLWD Total

0.260

0.191

0.272

0.277

1.000

Total Spkc if.s Richness

17

17

22

21

38

154

Great Basin Xatl i^alist

[Volume 58

(genus VVllA = 0.101), particularK E. clar-
ipennis (winter WRA = 0.058), and Orthocla-
(litis spp. (genus WHA = 0.075). especialK O.
riiicola (WRA = 0.071). Adult Tvetcnia vitra-
cies are common from autumn through spring
(0.06-0.021) and rare in summer (0.007).

The pre-impoundnient ri\ er was character-
ized b\' large late spring or early summer
floods. If non-Cricotopiis Orthocladiinae char-
acterized the pre-impoundment river, their
phenolog) ma\ reflect axoidance of spring and
sunnner floods, with oxiposition on the de-
scending, warming, or autumn limbs of the
hydrograph. Increased environmental con-
stancy (unithennal releases and reduced flood-
ing disturbance) and a shift in benthic sub-
strata from silt/sand to cobble (Howard and
Dolan 1981) favor species that apparently do
not recjuire warming cues and may emerge
throughout the year (e.g., some Cricotopns
spp.). As some thermal and substrate condi-
tions are restored over distance downstream,
total Chironominae WRA increases from 0.003
to 0.018 (Table 1).

The Colorado River chironomid assemblage
has changed during post-dam time. Stone and
Rathbun (1967 unpublished) noted only "blood
worms" (probabK Chironoiniis spp.) among
numerous aquatic invertebrate collections at
Lees Ferry immediately after impoundment.
Identification of 49 adult specimens collected
by Stevens (1976) in 1975 at Lees Feny reveals
an assemblage dominated by small-bodied
Cladotanytarsus sp., Tvetenia vitracies, and
Apedilum siihcinctwn, a species not collected
subseciuentK'. A total of 14 species collected
there from 1990 to 1992 show strong domi-
nance by Cricotopus spp. This chironomid
assemblage is likely to continue to change
through time as colonization occurs from tiib-
utaries and riverside springs, as extinction
occurs, and in response to dam management
policies.

ACKNOWLKIX'.MKNTS

This project was partially funded l)\ the
Hurean ol Heclamation Cllen ('anxon Ln\ iion-
mental Studies program, and partialK spon-
sored by the National Park Service C^oopera-
tive Parks Studies Unit Contract CA-8()09-8-
0002 at Northern Arizona University. We thank
D.W. Blinn lor project sii])p()rt and |. Maecalley,
C. Oberhn, and I". Yati's lor specimen j^repara-

tion. M. Sublette and R. Davis provided indis-
pensable assistance in the organization and
preparation of the manuscript. Two anonymous
re\'ie\\ers and C.C. Wiughn pro\ ided \aluable
conunents on earl\ drafts of the manuscript.

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Received 20 April 1997
Accepted 8 September 1997

Great Basin Naturalist 58(2), © 1998, pp. 156-166

SPOTTED KNAPWEED DISTRIBUTION IN STOCK CAMPS
AND TRAILS OF THE SELWAY-BITTERROOT WILDERNESS

W. Andrew Marcus', Gar\ Milner', and Bruce Maxwell-

Abstrac:t. — This article docuineiits sj^otted knapweed (Centaurca maculosa Lam.) in 30 campsites and alonji; 5 trails
in the Selway-Bitterroot Wilderness and assesses the role of disturbance and en\'in)nmental factors in controllinjj inles-
tation. Spotted knapweed was present in only 6 of 30 suneyed campsites and limited portions of all 5 trails that were
sampled. All spotted knapweed in camps was below 1700 ni elevation, in open canopy, and in areas with an opportunity
class disturbance ranking of 3 or 4. Overall disturbance levels measured using U.S. Forest Ser\'ice Site Impact Work-
sheets (SIXVs) did not help predict occurrence of spotted knapweed, although bare mineral soil, vegetation loss, and
development variables of SIWs provide some explanation of spotted knapweed presence or absence. There was no sig-
nificant difference in knapweed frequency between areas used predominantly by horses and those used by humans
within camps. Over 95% of spotted knapweed along trails was found within 0.5 km of the trailhead, occurred within 4.6
ni of the trail, and had low reproductive potential. If the Bittenoot portion of the Selway-Bitterroot Wilderness is repre-
sentative of forested wilderness areas in the Northern Rockies, then the perceived threat of spotted knapweed to wilder-
ness areas may substantially exceed the actual danger in many instances. Study findings indicate that managers should
conduct surveys before initiating costly control measures in wilderness areas, that eradication may be a viable alterna-
tive when spotted knapweed numbers are this low, and that regulations promoting minimum-impact camping should
reduce spotted knapweed infestation.

Kctj words: spotted knapweed, wilderness, management, disturbance, camp, trail.

Exotic plants pose a threat to wilderness
areas where they displace native species and
alter natural conditions that wilderness areas
are intended to preserve (Kummerow 1992).
Management policies on these public lands
now call for control of nonnative species to
preserve native plant communities (Westman
1990). Despite these policies, recent studies
have shown ever-increasing numbers of non-
native species in public lands of the Northern
RocW Mountain region (Losensky 1987, Lolo
National Poorest 1991, Whipple 1991, Tyser
and Worley 1992, Flathead National Forest
1993, Lesica et al. 1993).

One of the most pernicious e.xotic species is
spotted knapweed {Centaurea maculosa Lam.),
which covers vast areas of the American West.
This species is thought to be actively invading
the Selway-Bitterroot Wilderness Area of Mon-
tana and Idaho (Losensk)' 1987). Understanding
the mechanisms that allow invasion oi spotted
knapweed into this large wilderness area pro-
vides insights to the problem and ginclancc on
means of controlling this species in a \ariet\ ol
wilderness settings. I'his article documents the-

extent of spotted knapweed along trails and in
stock camps in the Bitterroot portion of the
Selway-Bitterroot Wilderness and e\aluates
the role of disturbance and environmental fac-
tors in controlling its extension in this area.

Spotted Knapw eed H.vbitat
AND Study Area

Spotted knapweed is native to the steppes
of Europe. Introduced to North America in
the early 20th centur\' as a contaminant in
'iurkestan alfalfa {Me(lica<i,() sativa L.) seed
((jroh 1940), it has, since that time, expanded
its range to co\er almost 3 million ha in the
northwest United States (Face\ et al. 1992).

Spotted knapweed in Montana has been
found in areas where average annual precipi-
tation is as low as 200 nnn/yr and as high as
2030 min/yr (Lace> et al. 1992), although Chi-
coine et al. (1985) fbimd most spotted knap-
weed in areas with axcrage ammal piecipita-
tioii between 310 and 7(iO nnn/yr. Sui"\i\al and
reprodnclion are enhanced if jireeipitation
coincides with seedling emergence iSciiirnian

'Ucparlniciil ollvirlli Sciences. Montana State I'niveisity, lio/.eiiian. MT.59717-(mH.

^Department i>( Plant, Soil and l£nvir<)nniental Sciences. Montana Stale University. Bo/.enian. MT.^UTIT.

150

1998]

Sl'OnKI) K\ AI'WKKD DiSTHIIUrriON

157

1981), and licMiiiiiiatioii increases witli increased
soil moisture content (Spears et al. 1980). Soil
t\ pc, however, does not appear to pla\ a major
role in detenninin<j; spotted knaiiwced distri-
bution (Scliinnan 19S I).

Olitimuni ti'mperatures lor uermination are
hetwcen KFC and 28°C: (Cliicoine 1984), and
tlif plant seems host adapted to areas with
90-120 Irosf-iree days (Clhicoine et al. 1985).
Spotted knapwt-ed in Montana has been docu-
mented at ele\ations from 579 in to 3048 m,
with 9(K^ of infested rangeland sites occurring
between (SIO m and 1829 m (Lacey et al. 1992).
Spotted knapwi'cd occupies e\'en' major habitat
t\pe west of the (Continental I3i\ide in Mon-
tana (Mooers and Willard 1989), although on
forested lands it is beliexed to pose the great-
est threat in the relati\ el\" low-King ponderosa
pint> iPiiius ])0)i(h'r()su Doug.) and Douglas-fir
{Psciidot.'>u<ia moizic'.sii [Mirbel] Franco) habitats
(Forcella and Han'ey 1983, Losenky 1987).

Disturbed habitat is a kc)' factor facilitating
spotted knapweed in\asion. Exposed soil, re-
duced canopy, irrigation, selective grazing of
iiati\e species, and contaminated hay all have
b(>en cited as causati\'e factors in the spread of
spotted knapweed (Watson and Renne>' 1974,
Morris and Bedunah 1984, Mooers 1986,
Losensk)' 1987).

Dispersion of Spotted Knapweed

Spotted knapweed reproduces only by seed
(Stor\- 1992) and disperses naturally through
peripheral enlargement (Watson and Renney
1974). Seeds are dispersed up to 1 m b\- a flick-
ing motion when the plant is disturbed. In
Montana seed production of spotted knapweed
axerages 1000 seeds per plant (Chicoine 1984).
French and Lac\ (1983) found that seeds ma\-
remain \ iable for up to 5 \'r, while Davis et al.
(1993) continued to find viable seeds into the
8th yr of their study.

Spotted knapweed rapidly expands along
roadwa) s and in fields as plants are caught up
in the undercarriage of farm machiner\ and
motor \ehicles (Montana Department of Agri-
culture 1986, Lacey et al. 1992). In presenes
and grasslands, priman' roads and motor \ehi-
cles help facilitate seed dispersal into adjacent
grasslands and trailheads (Tyser and Worley
1992). \\'ithin wilderness stock camps, where
use of motorized \ehicles is prohibited, spot-
ted knapweed can be introduced from seeds
in pack stock hay (Cole 1983, Marion et al.

1986) or within manure from animals that
ha\e consumed weed-infested feed (Dale and
Weaver 1974, Marion et al. 1986, Montana
Department of Agricnltin-e 1986). Seeds can
also adhere to damp tarp or tent bottoms or
become attached to humans or pack stock as
they moN'c along trails (Watson and Kenney
1974, Marion et al. 1986). Stock camps are
occupied by both humans and animals, but us-
ualK pack and saddle stock are kept separate
from the portion of the camp where humans
eat, sleep, and socialize. Thus, one might expect
more spotted knapweed to be present in stock
portions of the camp.

Early work suggested that spotted knap-
weed is allelopathic ((Chicione 1984), but later
research b\ Kclsex and Bedunah (1989) found
that allelopathy is not a significant factor con-
tributing to the spread of spotted knapweed.
Har\e\ and Nowierski (1989), howe\er, docu-
mented the possibility of spotted knapweed
displacing other species by depleting the soil
of phosphorus and other nutrients.

OBjKcrrivES and Hypotheses

This study documents spotted knapweed
distributions in camp sites and along trails to
determine the role of disturbance and select
environmental \ariables in controlling the
presence and abundance of spotted knapweed
in the Selwav-Bitterroot Wilderness. Specifi-
cally, we evaluate the hypotheses that spotted
kniapweed abundance will (1) decrease at higher
ele\'ations, (2) increase in areas with open can-
opy cover, (3) be greater in areas with higher
Forest Senice disturbance rankings and (4) be
higher in stock than in human portions of camp
sites. The number of \'iable spotted knapweed
seeds within 3 km of trailheads is also docu-
mented to assess the reproductive potential of
plants.

The primar\ objective of this work was to
pro\ide resource managers with an improved
imderstanding of (1) the extent of spotted knap-
weed infestations in the Selway-Bitterroot
Wilderness Ai^ea, (2) controls on spotted knap-
weed distribution in Northern Rock\ wilder-
ness settings, and (3) possible management
approaches for dealing with this problem.

Study Area

We chose the Bitterroot segment of the Sel-
wa>'-Bitterroot ^^'ilderness (Fig. 1) as a study

158

Great Basin Naturvlisi

[\blume 58

Selway-Blttarroot
Wllderneas

Fig. 1. Spotted knapweed study locations in the Selway-Bitterroot Wilderness Area. Solid circles indicate campsites
without spotted knapweed in 199.3. Solid triangles are campsites with spotted knapweed. Trails sunexed lor spotted
knapweed in 1994 paralk'l Bift Ik'ar, Mill, Sawtooth, and (-'halfin creeks. Trailheads ol'surxexed trails ran^e from 0.0 km
to 0..3 km upstream oi the wilderness houTidan with the exception ofChaffin C^reek trailhead, which is 3 km upstream of
the wilderness boundar\.

arcii hc'caiisc it receives regular use 1)\ hikers
and pack stock auci because spotted kuapwfcd
iu uou-w ilderuess portious of the liitterrool
National Forest is couuuon and considered out
of control (Losensky 1987). As of 1987 there
were l()9,(i()() ha within the forest iniested 1)\
the plant and another 284,524 ha at risk.
Long-distance spotted knapweed disjiersal has
been associated with conlaminatcd ha\ (I'or-
cella and Harvey 1983); stock camps in the
wilderness tlierelore may serve as points ol

weed coloni/atioii. Thc-ic arc thus ample set-d
sources, mechanisms ol seed tlispi-rsal, and a
suitable cii\ iiomnent for spotted knapwci^d to
invade the wilderness area.

We surxeyed 30 camp sites and 5 trails (Fig.
1), which ha\e ek'\ations ranging from appro.x-
imatcK 1400 m to 2400 ni. Precipitation in the
wilderness area langcs from 1800 nun at 2700
m cicxation in higlici- poitions ol the uoithcru
Mittenoot .Mountains to 025 mm in the lowt-i-
southeastern wilderness at appro.ximatcK 1200

1998]

Spotted Knapwkkd Distkiihtion

159

111 elexation ('Fiiiklin 1983). Mean montliK tciii-
peratures range ironi -8°C in Januan to 15°('
in Jnl\ at high elexutions and from -2°C in
Januan to 21°C in July at lower sites. Eleva-
tions, temperatures, and preeipitation in the
stuck area are all well within environmental
tolerance levels reported elsewhere tor spot-
ted knapweed.

Methods

We gathered data within stock camps and
along trails on spotted knapweed distribution
and on enxironmental and disturbance factors
that might attect the species. En\ ironmental
information included data on elevations and
canop\- and \egetation cover. Disturbance data
focused on le\el of disturbance, use by stock
or humans, and distances from trailhead and
trails. "Stock camps are used b> l)oth hikers
and packers. There are no designated back-
packer-oiiK camps or trails within the wilder-
ness area.

Thirty camps were sunexed between earl\'
June and late August 1993. Four of the camps
w ith spotted knapweed that were along sur-
\e\ed trails were revisited in 1994. Percent
co\ er of spotted knapweed, bare ground, rocks,
litter, moss, grass, forbs, shrubs, and trees was
sunexed using a modification of Cole's (1983)
method for determining wilderness impact
levels. Measurements were taken along 8 equal-
1\ spaced 24-m transects radiating from the
center point of the "human " and "horse " por-
tions of the camp. We differentiated human
and horse areas to determine if use txpe alters
spotted knapweed distribution and density.
Horse areas were defined on the basis of
manure, exposed roots, tree damage fiom teth-
ers, bare mineral soil, and observations by
wilderness rangers. Fire rings, fire scars, and
excaxated tent pads identified human areas of
camps. We used a 2-saniple / test to test the
null hxpothesis that there is no significant dif-
ference between the number of spotted knap-
xveed plants in human and horse areas of
camps. One camp x\ith xveeds xvas eliminated
from analx sis because horse and himian areas
could not be clearly separated.

Along each 24-m transect, xve located 2x2-
ni (juadrats 2 m apart; xsithin each (juadrat we
counted the number of spotted knapxveed
plants. To characterize vertical structure of the
canopy, xve xisuallx* estimated xegetation coxer

xariables at 3 heights: ground lexel to 50 cm,
51 cm to 3 m, and above 3 m. Scatteiplot analx-
sis xvas used to determine the relationship of
spotted knapxveed to vegetation xariables xvith-
in camp sites xvhere spotted knapxveed was
present.

Spotted knapxxeed distribution along 5 trails
xvas surveyed in August and September 1994
(Fig. 1). Starting at the trailhead and recording
the distance to trail-side infestations up to 20
m from the trail, xx'e recorded all occurrences
of spotted knapweed along each trail. At ran-
domly selected points of infestation along each
trail, a transect xxas established peipendicular
to the trail and 1-m- quadrats xxere placed at
trail center, 0.5. 1.2, 2.4, 4.6, and 20 m from the
trail. In each (}uadrat the percent canopy cover
of spotted knapweed and other species groups
(bare ground, moss, grass, herbs, shrubs, and
trees) xvas visually estimated and recorded.
Because all sampled trails paralleled streams,
xve recorded distances from the trail as nega-
tive (toxvard the stream) or positive (axvax' from
the stream).

Degree of disturbance in each camp and
along trails xxas initiallx determined based on
"opportunity classes" as defined on existing
Forest Serxice maps. The Selxvax-Bitterroot is
divided into 4 opportunity classes (Selway-Bit-
terroot W'ilderness 1992), xvhich are based on
degree of modification of the natural setting
and sites, degree of isolation, and frequency of
use. A ranking of 1 indicates a pristine, unvis-
ited region, while a ranking of 4 indicates a
largely unmodified region but xvith frequent
xisitation and locallx' significant alteration of
many of the destination sites.

W'e also determined disturbance at individ-
ual campsites using Selx\ax-Bitterroot Wilder-
ness Site Impacts Worksheets (SlW's), forms
used by all xxilderness rangers xxorking in the
Selxvay-Bitterroot and by managers through-
out the United States. SHVs are modified from
xxorksheets developed by Cole (1989) for docu-
menting wilderness impacts in campsites. The
second author of this article (CM) attended
the xvilderness ranger training session on
assessing disturbance xxitli the SIW' form and
xvas the onlx indixidual to collect SIW data
used in this study.

Degree of disturbance at a campsite is
assessed based on measures of 8 variables
(Table 1). Each xariable receives a rating rang-
ing from 1, xvhich is least disturbed, to 3, most

160

Great Basin Natuiulist

[Volume 58

Table 1. \'ariables, ratings, and weighting factors on the Selway-Bitterroot Wilderness Site Impacts Worksheets. Cov-
erage classes for vegetation and mineral soil are class 1: 0-5%; class 2: 6-25%; class 3: 26-50%; class 4: 51-75%; and
class 5: 76-100%.

W'c'ighting

\Uriahle

Definition

Rating 1

Rating 2

l^ating .3

factor

Vegetation loss

Ivstimated difference between

no difference

difference = 1

difference > 1

2

on-site and off-site coverage

in coverage

coverage class

coverage class

Mineral soil

Estimated difTerence between

no difference

difference = 1

difference >1

3

increase

on-site and off-site coverage

in coverage

coverage class

coverage class

Tree damage

Total iiuml)cr ol damaged trei-s

no more tlian

1-25 damaged

>25 damaged

3

ill the camp site

lirokeii lower

trees or >25%

trees or >50%

branches

trees damaged

trees damaged

Root exposure

Total number of trees with

none

1-15 exposed

> 15 exposed

3

exposed roots caused by-

roots or >25%

roots or >50%

erosion or trampling

trees exposed

trees exposed

Development

Number and type of facilities

no facilities

primitive log

facilities other

1

found w itliin the camp

or rock seat

than seat

Cleanliness

Amount of trash, fire scars, or

no fire scars

1 fire scar/ring,

> 1 fire scar.

1

manure at the site

or rings

some trash/
manure

much trash/
manure or
human waste

Social trails

Number of trails leading in

no more than 1

2-3 trails, max.

>3 trails.

2

and out of the camp

1 well worn

> 1 \\'ell wom

Barren area

Total barren area within the site;

<50 ft^

50-1500 ft-

> 1500 ff-

3

estimate

considered barren if >90% of
the vegetation is absent

disturbed. The ratiug for each variable is niul-
tiphed by a weighting factor. Types of impacts
that are easily remedied receive a weighting of
1. Impacts that are contained or could recover
with less use receive a 2. The hea\ iest weight-
ing of 3 applies to impacts that are difficult to
restore or arc long lasting. Weighted rankings
are then sunnned to determine overall camp-
site impact level, which can fall into 1 of 4
classes: light (18-27), moderate (28-36), heavy
(37-45), and extreme (46-54). SIW forms also
require noting whether the camp area has a
predominantly closed or open canop\-. A closed
canop\' is defined as branches from dillcrcnt
trees overlapping over the central campsite. A
complete copy of the 4-pagc SIW is contained
in Miluer(1995).

Opportunity class and SIW measures gen-
crate classes of disturbance ranging from 1 to
3 or 4, depending on the variabk' in (pustion.
Because of the small range of dislinbancc rank
values, a chi-s(|uare lesf was used to slalisti-
cally evahialc ihc disturbance li\ potheses.

Seed heads were collecled fioni spotted
knapweed plants within 3 km of the trailli( ads
along Mill (."reek. Big (]reek, and Bear Creek
trails (Fig. I). Seed was reinoxcd from the

seed heads and divided into plump, shrixeled,
and damaged seeds. Germination of the seed
was tested using a standard spotted knapweed
protocol (Davis et al. 1993).

Resuuis and Discission

Spotted knapweed occurred in 6 of 30 siu-
\e\ed campsites (I'ig. 1, Table 2). Knapweed
occurred along very limited portions ol all 5
trails, but nexer be\ ond 4.6 m from the trail or
7.6 km from the trailhead, with ()\er 95%
obserxcd within 0.5 km ol the trailhead (lug.
2, Table 3). More complete summaries ol the
N'egetation transi'ct and SIW distinbancc data
for each campsite are contained in Milner
(1995).

['"Ie\ alion

Ail (i camps containing spotted kna|)wi'ed
are located at <170() m, which is consistent
with C;hicoine et al. s (I9S5) work in Montana
showing 90% of inlestalion sites occurring at
<I829 m (6000 ft; lablc 2). There was no
spotted knapweed in any camjis or along an\
trails ab()\(' 1700 m, nor in 10 ol the Hi i'anii)s
ix-low 1700 m.

1998]

SK)Tri:i) KWI'W KKD Disthibution

161

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162

Great Basin Naturalist

[Volume 58

\s^r^<=-^

Fig. 2. Percent co\er of spotted knapweed relative to distance from trailhead (km) and peri^endicular distance (m) to Mill
Creek trail. Negative distance indicates distances on the stream side of the trail. Positive distances are on the upslope side
of the trail.

Canopy

Spotted knapweed was present in 6 of 10
open canopy camps below 1700 m, but not in
any of the 14 closed canopy sites, which in-
cluded 10 sites below 1700 m (Table 2). A chi-
square test indicated a significant relationship
at the 0.10 level between open canopy and
presence of spotted knapweed in camps (Table
4). Visual observations along trails also sug-
gested that spotted knapweed was more asso-
ciated with open areas and talus slopes in par-
ticular.

Open canopy can result from natural vari-
ability in forest cover but can also reflect dis-
turbance such as trampling and cutting down
of trees for firewood, ease of movement, and
facilities (e.g., hitches). Association of spotted
knapweed with open canop}' is consistent with
work by Watson and Hcnney (1974), who found
it to be more commonly associated with open
areas and rarely in shade. Losensky (1987)
noted that spotted knapweed germinates e(jual-
ly well under a 0-100% canopy, but shade
severely limits growth.

Disturbance and
Spotted Knapweed

Opportunity class and campsite infesta-
tion.— Five of 10 opportunity class 4 camps
and 1 of 8 class 3 campsites contained spotted
knapweed (Table 2). No infestations occurred
in 12 camps with ratings of Opportunit) class 1

or 2, which designate areas receiving less use.
A chi-square test indicated a significant posi-
tive relationship between opportunit> class
rank and spotted knapweed presence in camp-
sites at the 0.10 level (Table 4). The positixe
association of opportunity class and spotted
knapweed fits with previous research show ing
that disturbance plays a key role in facilitating
spotted knapweed infestation (Watson and
Renney 1974, Morris and Bedunah 1984,
Mooers 1986, Losensky 1987).

Site impact rating and campsite infest.\-
TION. — Unlike the clear association of oppor-
tunity class and spotted knapweed, the o\erall
SIW rating for campsites (moderate, hea\\',
extreme) did not have a significant relation-
ship to presence or absence of spotted knap-
weed in the Selwa\ -Bitterroot Wilderness
(Table 4). This is probabK because the o\erall
SIW rating gives significant weighting to a
number of variables such as cleanliness, root
exposure, and tree damage which, based on
existing literature, would not be iwpected to
ha\c' a direct conneetion to spotttnl knapweed
presi-nce or absenci'. In eonfrasl, opportunit)'
classes are largely di'lined based on freciuenc)'
of use and piobabK pro\ ide a betti'i" indicator
of total numbers of users and the resultant dis-
turbanci' and potential for seed introduction.

Some components of disturbance that are
measured to determine the overall SIW rating
do, however, appear to be associated with

1998]

SFOITEU K.NArWEEL) DlSTUIBLTlOxN

163

Tabi.k 4. Cln-s(iiiare test of the relationship between
nunil)er of spottt-d knapweed at eadi campsite (» = 30)
and possible drivinii \ aiiahles. l-lelationships significant at
the 0.10 le\el are in boldface.

\arial.lc

c:l

li-siiiiare

P ^ alne

Opportunit) class

S.90

0.019

Xariahles on SIW siiix't

Xegetation loss

4.36

0.113

Mineral soil

3.96

0.138

Tree daniaue

0.17

0.680

Root exposnri'

1.29

0.256

De\eIopnR'nt

5.83

0.054

Cleanliness

3.40

0.183

Social trails

1.96

0.375

Banen core area

1.09

0..581

Closed/open forest c

anop)

5.64

0.010

Overall SIW impact i

atini;

1.47

0.537

spotted knapweed. Although not .significant at
tlie 0.10 le\el, \egetation loss and mineral soil
\ariables both show weak associations with
the presence of spotted knapweed in camps
(Table 4). This suggested link between vegeta-
tion loss, mineral soil, and presence of spotted
knapweed is consistent with previous research
indicating that exposed mineral soil proxides a
fertile area for spotted knapweed germination
(Morris and Bedunah 1984, Mooers 1986).

The apparent association of the dexelopment
\ariable with spotted knapweed (Table 4) is
perplexing. Development as defined on the
SIW is the number and t\pe of facilities (e.g.,
tent poles, log seats, hitch rails, etc.). Four of
19 camps with a de\elopment rating of 3 (the
most developed) and 2 of 4 that rated a 2 con-
tained spotted knapweed (Table 2). None of the
7 camps with a dexelopment rating of 1 con-
tained the weed.

The apparent preference of spotted knap-
weed for development rating 2 sites may sim-
ply reflect the ele\ ations of camps with open
canop\ rather than a preference for sites with
intennediate levels of development. Three of 4
de\elopnient rating 2 camps are situated below
the 1700 m ma.ximum elexation at which spot-
ted knapweed was found in this stud\, while
onl\- 5 of 19 development rating 3 sites are
located below 1700 m. Approximately equal
proportions of de\elopment rating 2 and 3
camps below 1700 m thus contain spotted knap-
weed. Xone of the de\elopment rating 1 camps
contain spotted knapweed, but all are located
above 1700 m. Greater development is also
associated with open canopy because trees are

felled to make hitches, tent poles, seats, and
other facilities.

Disturbance and infestation along
iKAli.s. — Spotted knapweed occurrence along
trails is limited in extent, generally occurring
in low-elevation, most frequently visited por-
tions of trails within 0.5 km of trailheads (Fig.
2). Disturbance as indicated b\' opportunity
class ranking also is associated with infesta-
tion, with the large majority of weeds growing
along the opportunity class 3 and 4 trail sites
(Table 3). Spotted knapweed occurred at only
3 open scree sites along the opportunity class
2 Sawtooth Creek trail.

In general, spotted knapweed is most com-
monly observed along all trails on scree slopes
where soil is shallow and rock is often moving
over and disturbing the surface. Spotted knap-
weed cover decreases with distance from the
trail (Fig. 2), which may be the result of de-
creased disturbance associated with activity
on the trail or increased distance from sources
(people and animals) traveling along the trail.
There is also a decrease in knapweed fre-
(juenc)' and cover with increased distance
from trailheads (Fig. 2). These results are simi-
lar to those described bv Dale and Weaver
(1974).

Stock and Human Use Areas
in Camps

In the horse areas of the remaining 5 camps,
16 of 1355 quadrats contained a total of 84
spotted knapweed. In hinnan areas, 13 of 1264
(juadrats contained 51 total plants. At the scale
of individual campsites, our data indicate no
significant difference in spotted knapweed fie-
(]uenc\' between horse and human areas.

Vegetation in Camps

A Pearson conelation of vegetation cover and
spotted knapweed abundance was conducted
to determine if local scale variations in ground
cover affect the ability of spotted knapweed to
colonize. We limited our analysis to the 16
camps below 1700 m where spotted knapweed
was known to be viable. The correlation sup-
ports the general observation that canopy is
ke\' in controlling spotted knapweed (Table 5).
The onK correlation that was significant at the
0.05 level was the negative correlation (r =
0.08) between tree cover above 3 m in height
and spotted knapweed density'.

164

Great Basin Naturalist

[\blume 58

Table 5. Pearson correlation coeBkients (r) tor co\er
categories {%) versus spotted knapweed stem density
(stems/m-) in the 16 camps below 1700 m ele\'ation.

Co\'er variable

Hari' lirouiid

Litter

Moss

Forbs

Grass

Brush (<3.0 m)

Trees {<3.0 m)

Brush (>3.0m)

Trees (> 3.0 m)

0.0077
-0.03.57

().01H4

0.0121
-0.0 LSI

0.0178
-0.0377
-0.0160
-0.0802*

*Significant conclation i p < 0.0.5

In 6 camps where spotted knapweed was
present and where cover could influence the
within-camp distribution, scatterplot analysis
indicated that spotted knapweed does best in
areas with <259c co\'er of rock, which simpK'
reflects the inability of the plant to grow with-
out soil. In general, spotted kniapweed was pres-
ent only in quadrats where percent cover of
litter, moss, grass, and trees was each <25%,
or the total canopy cover was < 100% (canopy
coxer often exceeded 100% because it was mea-
sured in 3 different levels and then summed).
This is consistent with Morris and Bedunah's
(1984) and Mooers' (1986) findings that bare
soil enhances the ability of spotted knapweed
to invade a site. Percent cover of forbs sho\\ ed
no clear relationship to spotted knapweed.

Spotted knapweed, however, was usualK'
present only in quadrats with <25% bare
groimd. This partially results because spotted
knapweed covers the soil and reduces the per-
cent cover of bare ground. In addition, man\
areas with significant bare ground in camp-
sites are locations where fire rings, tent sites,
and horse hitches are concentrated. While
some bare ground is beneficial to spotted knap-
weed, areas that receive repeated disturbance
and soil compaction can make it difficult for
any new plant, including spotted knapweed, to
become established.

Seed and Plant \ial)ilit\

In 1994 no knapweed was obserxfd in 3 of
4 camps that were infested in 1993. This sug-
gests that spotted knapweed may be ephemeral
in the wilderness and present onK under ideal
growing conditions.

In plants sampled along Mill, iiig, and ik-ar
Creek trails, there was a mean of 16 (±12)

seeds per head. This is substantialK lower than
the 1000 seeds per head generalK' reported.
The proportion of plump seeds ranged from
2% to 100% of seeds in indi\'idual heads. No
shriveled or damaged seeds germinated, but
1009^ of plump seeds did. Thus, one nia\ eon-
elude that \iable seed is produced in the
wilderness but reproductix <.• potential is low.

Man AGE. ME NT Implications

It is notable that onh 6 of 30 wilderness
campsites and very small portions of 5 wilder-
ness trails contained spotted knapweed in an
area perceived to be at great risk from infesta-
tion. Furthermore, spotted knapweed occurred
in onh' 1 of 4 camps infested in 1993 that were
revisited the following summer, and seed pro-
duction was low for specimens collected along
the trail during the summer of 1994. If the
Bitterroot portion of the Selwa\-Bitterroot
Wilderness is representative of forested w ilder-
ness areas in the Northern Rockies, then the
percei\'ed threat ma>' substantialK' exceed the
actual danger in many instances. The results
from this study suggest 4 general a\ enues of
management responses .

(1) Managers should conduct sin-\c'\s before
initiating costK' control measures in an\ w ilder-
ness area. Sur\e\s in forested regions similar
to the Selway-Bitterroot should initialh- focus
on areas most prone to infestation, that is, areas
with open canop\ adjacent to trails where
opportunity class ratings are 3 or greater and
in ele\'ations that are optimal for sjiottc-d knap-
weed.

(2) Wilderness workers can be trained to re-
moxc weeds as part of their normal backeomi-
tr\ duties. Likewise, xolunteers can be educated
and recruited to renune weeds \ia existing
weed awareness programs, signing of trails,
and inlorniation [laekels gixcn to baikeouiitrx
users.

(.3) The association ol siiotted kiiaiiwi-ed at
campsites with loss of xt'gi-tation. exposed min-
eral soil, opi-n canop), and dexclopnient ol facil-
ities emphasi/es the need loi' airi'acK I'xisting
regulations promoting minimuni-inipaet camp-
ing in wikkMuess areas. In particular, baekcoun-
lr\ permits should stri-ss packing in camp chairs
and using aliMninnm pok's lor tent poles and
hitches rather than tearing down dead wood or
cutting li\(' tices, both ol whiih o|)en up the
canoi)y

1998]

Spo'ITKI) K\ ai'\\i;i;i) Disriiim i lox

165

(4) Tlu' ti'iulciK'y lor spotted knapweed to
<4row oiiK on scree slope's alonii; trails snggesls
that inleslation eonld he a\()idecl b)- rontinii;
tiails to a\()id these open distnrhed areas.

This feseaieh lea\es open the (^nestion oi
how serious the spotted knapweed problem is
in surronnchnu forested, non-wilderness por-
tions ol the Hitterroot National Forest and
\\ hether the same \ariables of ele\ation, open
eanopy. and opportnnit\' elass can be nsed to
pri'diet potential lor infestation on those lands.
Hiere is ilearK a \ast _ii;nlf between the per-
(-•(.'ptiou ol infestation and the realit\' in some
areas. This nneertaint\ suggests that, at a nnn-
inuun. hirthei' sur\e\ s should be conducted in
ditlereut use areas to determine wliere the
tlueat is serious, what \ariables control that
threat, and how to best allocate resources to
control spotted knapweed.

Ack\o\vled(;ments

This research was funded b\' the Mountain
Kesearch Center, Montana State University.
Peter Fa> and Katherine Hansen of Montana
State Uni\ersit\ pro\ided useful suggestions
lor the research design and anaKsis.

Literature Cited

CiiieoiNL;, T.K. 1984. Spotted knapweed (Ceiitdiirid mac-
ulosa L.) control, seed longe\ity and migration in
Montana. Unpublished master's thesis. Department
of Agrononn, Montana State Lni\ersit\', Bozeman.
83 pp.

Ciiic;oim:, T.K., PK. F.w, .wd J. Nielsen. 1985. Predicting
weed migration from soil and climate maps. \\'eed
Science 34:57-61.

Cole, D.N. 1983. Monitoring the condition of wikleniess
campsites. Research Paper INT-3()2. Intennoiintain
Forest and Range E.\periment Station, USD.A Forest
Sen ice. Ogden, UT. 10 pp.

. 1989. Wilderness campsite monitoring mi-tliotls: a

source book. General Technical Report INT-259.
Intemiountain Research Station, USD.\ Forest Ser-
vice, Ogden, UT. 57 pp.

D.\LE, D., WD T. We.WEK. 1974. Trampling elfects on \cge-
tation of the trail comdors of north Rockx Mountain
forest. Journal of .\pplied Ecology 1 1:767-772.

D.wis, E., RK. Fay, TK. Ciiicoine, and C.A. Lacev. 1993.
Persistence of spotted knapweed (Cenfaiirea imiculosa)
si'cd in soil. Weed Science 41:57-61 .

FiNKLlN. A.I. 1983. Weather and climate ol the Selwa\-
Bitterroot Wilderness. Universit\- Press oi Iilalio.
Moscow. 144 pp.

Flathead N.\tional Forest. 1993. Final environmental
impact statement, 1993, noxious weed management
project. Spotted Bear and Hungr>- Horse Ranger
Districts. Flathead County. Montana. Flathead Na-
tional Forest. USD.\ Forest Service, Kalispell. .MT.

I'diu 1 1 i.\, !■:. \\i) S.J. Mah\EY. 1983. Eurasian weed in-
leslation in wi'stern .Montana in relation to vegeta-
tion disturbance. Nhidrofio 30:102-109.

(".Hon, 11. 1940. Turkestan alfalfa as a medium ol weed
intioduction. Science in Agriculture 2I:.3(i-43.

IIah\i;v, S.J., AND R.M. Nowiekskl 1989. Spotted knap-
weed: allelopathy or nutrient depletion? Page 118 iti
HK. Fa\' and J.R. Lacc-\. i-dilors. Proceedings of the
1989 knapweed s\ iniiosiuni, Montana State Univer-
sity, Bozeman.

Kelsey, R.G., AND D.J. Bi 1)1 wii. 1989. Ecological signif-
icance of allelopath\ lor ('cittaiirea species in the
uorthwesteiTi United States. Pages 10-32 in PK. Fay
and J.C Lacey, editors, Proceediirgs of the 1989
knapweed s\in])osiuni, Montana State- Unixcrsity,
Bozeman.

Ki \i\ii;ii()\\. M. 1992. Weeds in wilderness: a threat to
biodi\ersit\. Western Wildlands 18:12-17.

Lacey, C.A.. J.R. Eycey. PK. Fay, J.M. Story, and D.L.
Zamoha 1992. Controlling knapweed on .Montana
rangeland. .Montana State University E.xtension Ser-
\ ice Bulletin 2C0311, Bozeman, MT. 6 pp.

Lesica, R, K. Ahlenslager, and J. Desanto. 1993. New
\'ascular plant records and the increase of exotic
plants in Glacier National Park. Montana. Madroiio
40:126-131.

LoLO National Forest. I99I. Noxious weed manage-
ment, final environmental impact statement, 1991,
amendment to Lolo National Forest Land and
Resource iManagement Plan. Lolo National Forest,
Fort Missoula, Missoula, \i T.

Losensky, J.B. 1987. An e\aluation of noxious weeds on
the Lolo, Bitterroot and Flathead forests with rec-
ommendations for implementing a weed control pro-
gram. Lolo .National Forest, Fort Missoula, .Missoula,
MT 64 pp.

Marion, J.L., D.N. Cole, and S.P Br.\tton. 1986. E.xotic
vegetation in wilderness areas. Pages 114-120 in
R.C. Lucas, editor Proceedings of the national
wilderness research conference: current research.
General Technical Report INT-212. Intemiountain
Research Station, US DA Forest SeiAice, Ogden, UT.

MiLNER, G.M. 1995. The relation between disturbances in
stock camps and the occurrence of spotted knap-
weed (Centaurea maculosa) in the Selway-Bitterroot
Wilderness in Montana and Idaho. Unpublished mas-
ter s thesis. Department ol Earth Sciences, .Montana
State Universitv; Bozeman. 83 pp.

-Montana Department of .Acricii.tirk. 1986. Weed train-
ing manual. EnviromncTital Management Di\ision,
Helena, MT. 3 pp.

MooERS, G.B. 1986. Relationship of critical environmen-
tal factors to the success of spotted knapweed {Cen-
taurea maculosa L.) in western Montana. Unpub-
lished master's thesis, Universit}- of Montana, Mis-
soula, MT.

MooERS C.B., AND E.E. \\ ii.i.AHD. 1989. Critical emiron-
mental factors related tc; success of spotted knap-
weed in western Montana. Pages 126-135 in RK.
Fa\ and J.R. Lacey, editors. Proceedings of the 1989
knapweed s\nip()sium. Montana State University,
Bozeman.

Morris, M.S., and D. Bedinah. 1984. Some observations
on the abundance of spotted knapweed (Centaurea
maculosa L.) in western Montana. Pages 77—80 in
J.C. Lacey and PK. Fa\. editors. Proceedings of the

166

Grkat Basin Naturalist

[Volume 58

knapweed symiposiiim. Cooperative Extension Service
Bulletin 315, Montana State Universit\', Bozenian.

SCHIRMAN, R. 1981. Seed production and spring seedling
establishment of diffuse and spotted knapweed.
Journal of Range Management 34:45 — 17.

. 1984. Seedling establishment and seed produc-
tion of diffuse and spotted knapweed. Pages 7-10 in
J.R. Lacey and P Fa\, editors, Proceedings of the
knapweed symposium. Cooperative E.xtension Service
Bulletin 315, Montana State University, Bozeman.

SELW.AY-BnTERROOT WILDERNESS. 1992. Selwav-Bitter-
root general management direction, 1992 update.
Nez Perce, Clearwater, Lolo and Bitterroot National
Forests. U.S. Department of Agriculture, Bitterroot
National Forest, Hamilton, MT.

Spe.\rs, B.M., S.T Rose, .and W.S. Belles. 1980. Effect of
canopy cover, seeding depth, and soil moisture on
emergence of Centaurea maculosa and C. diffusa.
Weed Research 20:87-89.

Story, J. 1992. Biological control of weeds: selective, eco-
nomical and safe. Western Wildlands 18:18-23.

Tvser, R.W., AND C.R. WoRLEV. 1992. .Alien flora in grass-
lands adjacent to road and trail corridors in Glacier
National Park, Montana (U.S..\.). Conservation Biol-
ogy 6:253-262.

W.^TSON, A.K., AND A.J. Rennev. 1974. The biology of
Canadian weeds, Centaurea diffusa and C. maculosa.
Canadian Journal of Plant Science .54:687-701.

Westman, W.E. 1990. Park management of exotic plant
species: problems and issues. Conservation Biology
4:251-259.

Whipple J. 1991. Exotic plant list of Yellowstone .National
Park. U.S. Department of Interior, Yellowstone Nation-
al Park. Mannnoth Hot Springs, W^'. 1 pp.

Received 19 Januanj 1996
Accepted 19 August 1997

C.R-at Basin Naturalist 58(2), © 1998. pp. l(i7-lS;3

BREEDING BIRDS AT THE IDAHO NATIONAL ENGINEERING
AND ENVIRONMENTAL LABORATORY, 1985-1991

JaiiR's K. Bc'ltlioll'. Ix'oii 1{. Powers-, and I iinotliN D. Hexnokls^

.•\BsrH.\(:r. — Diuiiiu the siiiiuiii'is ot UiS.o-lfjyi. bird iciisusi's were coiidiicti'd aloiii; 1.3 i)i'riiiaMent routes loeated at
the 2.'31.5-kni- Idaho National Kngineering and Knvironniental Lahoratoiy (INEEL, iomierly INEL) in southeastern
Idaho. The ohjecti\es of the sune\.s were to (1) compare a\ifaima in and near facility complex sites with remote, rela-
tiveK' imdisturhed habitats, (2) identify trends in populations of saj^ebrush-ohligate .species and other common shrub-
steppe species, and (3) determine the presence, abimdance, and population status of species of special concern. Five
routes were oflkial U.S. Gcoloj^ical Sur\'e\', Biological Resources Division 40.0-km Breeding Bird Survey (BBS) routes
(formerly administered b\' the U.S. Fish and Wildlife Service) located in relatively remote portions of the INEEL where
access by humans was controlled and limited. Eight shorter routes (5.8-19.2 km in length) were near INEEL facility
comple.xes, which more regularly experienced disturbance by hinnans. The suneys recorded 25,597 individuals repre-
senting 90 species. Western Meadowlarks {Stiirnella neglecta). Brewer s Sparrows (Spizella hreweri). Sage Sparrows
{Ainphi.spiza IwUi). Homed Larks (Eremophila alpestris), and Sage Thrashers (Oreoscoptes montanus) comprised 72% of
all indi\iduals. Almost halt of all species were represented by fewer than 10 individuals. Bird density was significantly
greater along facilit\ complex routes. M()reo\er, because of human-constnicted wetlands and structures of various types,
facilit) complex routes had signifkantly more t)ird species per unit area, including more species of waterfowl and human-
associated species. Some year-to-year variation in bird densit)' was related to weather More individuals were recorded in
cooler, wetter \ears, although such increases were reflected more along facilit\' complex routes. Among sagebrush-oblig-
ate species, trend anaKsis suggests that both Brewer's Sparrows and Sage Spanows increased significantly in abundance,
which ma\' be in contrast to regional trends for these species. Of 5 species of special concern observed, trend analysis
could be perfonned for onl\- 2: Ferruginous Hawks [Biiteo regalis) and Loggerhead Shrikes (Lanius ludovicianu.s). Both
species had more routes with negative regression coefficients and negative trend means, indicating that declines may
have occuned, although the goodness-of-fit test for neither species was significant. These data from the INEEL should
be useful for comparison with future studies at the site and other studies from tliroughout the Great Basin region.

Key words: Idaho Xatiomd Engineering and Environmental Laboratory (INEEL), avifauna, sagebritsh shnd)steppe,
sagebrush obligates.

Although a number of recent reports docu-
ment population changes in the avifauna of
the eastern or midwestern U.S. (e.g., Askins et
al. 1990, Sauer and Drocge 1990, 1992, Hagan
and Johnston 1992, Finch and Stangel 1993,
Hagan 1993, Peterjohn and Sauer 1994, Hek-
ert 1995), patterns of population change in
western bird species ha\e remained largely
understudied. Dobkin (1994) noted that fewer
studies in the West may be a result of fewer
Breeding Bird Survey routes and proportion-
atel\- greater non-urban/suburban habitat com-
pared to the eastern U.S. Additional!); insuffi-
cient route coverage over much of the western
U.S. has limited attempts to compare trends
between periods in BBS data for populations
of many western species (e.g., see Sauer and
Droege 1992). Despite such limitations, Paige

(1990) indicated there are key species in every
major habitat in the West that warrant either
concern or immediate action. Of particular
interest in her analysis were shrubsteppe and
grassland habitats, which apparently experi-
enced widespread declines in avifauna between
1966 and 1985 (Paige 1990). Additional and
more recent information concerning avian pop-
ulations in shrubsteppe and grassland habitats
would be useful to determine whether such de-
clines have continued or have been exacerbated.
The Idaho National Engineering and Envi-
ronmental Laboratory (INEEL), located in
southeastern Idaho, is a federal facility con-
taining large expanses of shrubsteppe habitat
within its boundaries. In contrast to many other
sites in southern Idaho and elsewhere where
this habitat t\'pe has been converted for crop

'Department of Biolog\. Boise State Cni\ersit>, Boise, ID S.372.5.

^Department of Biology, Northwest Nazarene College, Nampa, ID 83686.

^Environmental Science and Research Foundation, 101 S. Park Avenue, Box .5I83S, Idalio Rills, ID 8.340.5-1838,

167

168

Ckkat Basin Natl kalis i

[Volume 58

and lia\' production, or severely altered by
in\asion of exotic species of annuals, shrub-
steppe habitat at the IN EEL remains relatively
undistuibed because there are few roads, access
by humans to nmch of the area is controlled
and limited, and there is no crop or hay pro-
duction. Instead, this area was designated as a
National En\'ironmental Research Park in 1975
and senes as an outdoor laboratorx' to assess
impacts of energ\' dexelopment technologies on
the environment. Although the vertebrate fauna
on the area ha\ e been described (Reynolds et
al. 1986), little information exists concerning
how the avifaima changes with time, or how
changing land-use patterns and other activi-
ties affect the structure or abundance of avian
populations. Therefore, because of the paucity
of information on population status of breed-
ing birds in the western U.S., and because the
INEEL provides an ideal study site for con-
ducting longer-term studies within shrubsteppe
habitat, we examined the avifauna by census-
ing permanent survey routes for birds each
summer.

Specifically, our objectives in the present
study were to (1) identify' bird species present
at the INEEL during the summer breeding
season; (2) assess the effects of INEEL activi-
ties by comparing the abundance and compo-
sition of avifauna occupying facility complex
sites and more remote habitats; (3) identify
trends in abundance of sagebrush-obligate
species (i.e., species characteristic of the shrub-
steppe habitat that recjuire large areas of un-
fragmented sagebrush habitat) and other com-
mon shrubsteppe species; (4) determine the
presence, abundance, and population status oi
species of special concern in Idaho; and finalK
(5) generate baseline information concerning
populations of breeding birds at the INEEL,
which hopefully will be useful lor comparisons
with ongoing and future studies both at the
site and in slirul)stc])pc habitat tlnoiighout the
western U.S.

Sn i)V Arka

The 2315-km2 INEEL is located approxi-
mately 48 km west of Idaho l-alls, on the
upper Snake River I'laiii in portions ol iion-
ne\ille, hiittc, l^ingliani, jcirc ison, and (llark
counties, idalio. The area is dominated b\ semi-
aiid, cold desert slnnbland willi an axcrage
elexalion ol a|i|ii()\iniatel\ 1.100 ni al)o\e sea

level. The climate, geology, and xegetation of
this high desert area are described in detail b\
Anderson and Holte (1981) and Anderson ct al.
(1996). BriefK; vegetation at the site is charac-
teristic of shrubsteppe habitat and dominated
b\ woody, mid-height shrubs and perennial
bunchgrasses. Common plant species include
sagebrush {Artemisia spp.), rabbid)iush iChn/so-
thamtms viscidiflonis), shadscale iAfrii)h'x con-
jertijolia), winterfat {KrasclH')ii)iiiik()vi(i lanata),
squirreltail (Elynuis elymoides), thickspike
wheatgrass {Ehpinis Janceolatus), needle and
thread grass {Hcsperostipa cotnata), and rice-
grass {Aclinathcnim Injmcnoides). In general,
the topography is flat to gently rolling, with
lava outcroppings characteristic of the Colum-
bia Plateau Proxince. The area experiences hot
summers, cold winters, frequent wind, and low
soil stability (Short 1986). Annual precipitation,
averaging approximately 20 cm/ yr, is produced
mainly during spring rain and snow e\'ents.
Sm-face water is limited to residual flows of the
Big Lost Rivers and Birch Creek, each of which
is diverted upstream for agriculture and flood
prevention, and several (0.3-15.8 ha in size)
human-constructed ponds near research facili-
ties. Grazing by sheep and cattle occurs but is
seasonal and concentrated on the peripher\' of
INEEL where the site borders Bureau ol
Land Management (BLM) and pri\ate holdings.
Stocking densities in areas grazed at INEEL
are lower (10 ac/AUM) than those on neigh-
lioring BLM lands (6 ac/AUM).

Methods

Sune\' Routes and l^ocedures

Thirteen permanent a\ian census routes
were established w itliin the stud>' area (Fig. 1).
These include 4().()-kni routes {)i = 5 standard
Breeding Bird Sur\c'\ [BBS] routes adminis-
tered b\' U.S. Cieological Sur\e\, Biological
Resources Di\ision) that traxerse the major
habitat t\pes within more remote regions ol
the site (Table I, Fig. 1). Foi' brexitx, hereafter
we reler to these as rcntolc routes, and the
areas in which the\ are located as remote
(ircds. I'j'glil sliortei' routes, axcraging 8.5 km
in length, are aionnd niajoi' INEEL facilitx
complexes (Table I ). wlieii' ellects of site aitixi-
tii's on the abundance and composition ol ax i-
launa are assessed in comparison to remote
areas. We reler lo lliese routes as Idcililtj com-
plex roiiles. rlie 13 routes were sur\e\ed loi'

19981

Biii;i:i)i\(; I^ikd Cknsls at INEEL

169

Tmu I 1. Sumniaiy of Ii'iiutli ol route, iuiuiIht of stops, and area siinexed alonu pennaiK'iit bird simey routes (;i = 5
rciiiott' routes, » = 8 faeilit\ couiplt-x routi's) at the Idaho National Eii\ ironniental and I'jinineeiin^ Lahoiatorv in
southeastern Idaho. Major habitat associations along each imilc mil mean (± .v) number of species and indi\ itluals (nuni-
ber/kni-) obser\ed along each route, 19(S5-199I, also are summaii/id.

Length

No.

Art'a

No.

No.

Major habitat types-'

Kouti'

(km)

stops

(km^)

species

individuals

([jercentage of route)

i{i Mori-: iu)iTi;.s

Iwin Buttes(TB)

10. 1)

.50

25. 1

17.3 ± 1.9

12.9 ±3.4

1 (16), 2 (31j, 8 (16), 9 (12),
11(17), 13(4), 15(4)

Lost |{i\er(LR)

10.0

.50

25.1

15.8 ± 1.3

12.3 ±3,4

1 (76), 3(12), 12(12)

K\k' (.auNon (KC)

K).0

50

25.1

22.8 ± 3.9

11.7±2.7

3 (20), 4 (20), 6 (10), 7 (12),
11(16), 12(14), 14(8)

Circular Butte (CB)

40.0

50

25.1

13.0 ± 1.5

13.0 ±5.5

2 (4), 3 (6), 5 (60), 10 (20),
12(10)

Tractor Flats (TF)

40.0

.50

25.1

17.3 ±2.3

18.9 ±6.1

1 (8), 2 (23), 8 (7), 10 (40),
13 (22)

F\(:ll.ir\ COMI'I.KX HOITES

Idaho C'heniical i^roeessing

Plant (ICPP)

8.0

25

2.01

13.4 ±1.8

88.0 ± 30.6

3(100)

Test Heactor Area (TFL\)

10.2

32

2.57

13.4 ±3.6

102.2 ±60.1

3 (100)

Central Facilities Area (CFA)

9.6

421.

.3..38

18.6 ±1.5

88.3 ± 19.4

2 f75), 3 (25)

Na\al Reactors Facilit\ (NHFi

(i.4

20

l.ftl

22.4 ±5.4

168.7 ±57.4

2(100)

Test Area North (TAN)

19.2

fiO

4.82

18.1 ±4.0

92.2 ± 40.6

4 (40), 10 (15), 14 (45)

Power Burst Facility (PBF)

9.0

28'^'

2.25

12.1 ± 1.9

81.1 ±28.3

2 (80), 13 (20)

Radioacti\c Waste Management

Complex (RWMC)

5.8

18

1.45

12.7 ±2.4

72.3 ±11.1

1 (100)

Argonne National

I .aborator\ -West (ANL-W)

.5.8

IS

1.45

20.1 ±3.5

136.9 ±27.8

2 (SO), 15(20)

•'Habitat types: (1) Aiieiiiisia IrUlentata-Pseudoroegneria sincatu-Chnjsotlmmmis viscidiflonis, (2) Artemisia tridentalu-Chnjaothuinnwi viscUliflorus-Elyinus
ehjmoides, (3) Arttnnisia tridenlata-Elymus lanceolatus-Hespewstipa comata. (4) Artemisia tridentata-Kraschcninnikovia kmitii-Clirysothammis viscidiflonis. (5)
Artemisia tridentata-Achnathcntm hijmcnoides-Hesperostipa comata. (6) Artemisia tridentala-Kruschcninnikovia laimta-Atriplex confrrlifoUa. (7) Artemisia
arhiiscula-Artcmusiu tridentata-AtripIex confertifolia. (H) Afiropynm crislatiim (st-fck-d), i9) I'semloniccncria spicala-.Aileinisia trip(irlila-(:Uni\olliamnwi vLscidi-
florti.s. (10) Achiiuthenim lttjmen(mh:s-Chry.mthammis ciscidifloru.s-C>pimlia pohjucanthu. ' W) Jimipeni.s ostC(isi)rrmu-.\rtemixia li-idciitala-Psiiiiloroe^neria .ipi-
cata. (12) Tctradymia canescens-Chrysothammts visciiliflorus-Artemi.sia tridentata, (13) Chrysothamniis viscidiflorus-Artemi.\iu tridentala. (14) Atriptex
miltalii-Kra-icheniimikoiia lanuta-Achnathenmi hymenoides. (15) Leymtts cinereiis-Chrysothammi.'s viscidiflorus-Pseudorocgneria spicata.
'■Only .30 stops were included in 1985.
rhirty stops made in UWfi

l)iids in June of each year between 1985 and
1991, with the exception of 4 individual route
surveys (3 in 1985, 1 in 1990), which were per-
formed in earl)' JuK because of delays caused
b\ unsuitable weather. Beginning 0.5 h before
sunrise, we recorded the number of individu-
als of each bird species seen or heard during
3-min obsenation sessions at each stop along
the route. For remote routes, we located stops
e\'er\- 0.8 km and counted biids if tlic\
occurred within 0.4 km ot the stop. Sur\e\s
along the shorter lacilit\ complex routes were
performed in a similar fashion, except that stops
were 0.32 km apart and birds were recorded
onK if diey were within 0.16 km (i.e., half the
distance between stops) of the observer. Stops
were \isited in the same order each >ear but
sur\e\s were conducted onl\ when weather
conditions were considered satisfactoi-) accord-
ing to BBS guidelines.

FinalK; 4 different obseners performed the
sui-\e\s. Because 3 obserxers each performed

the surveys for 2 consecutive years (1985-86,
1987-88, 1990-91), and the 4th conducted sur-
veys in only 1 yr (1989), the possibilitx of
interobsener (Sauer et al. 1994) and Ist-time
obserxer (Kendall et al. 1996) effects in the data
set cannot be rided out. For example, Kendall
et al. (1996) noted that trend estimates for many
species l)ased on formal breeding bird survey
route data decreased by an average of 1.8%
per xear when data from an obseners 1st yr
were excluded, and the authors suggested the
difference was most likeK a result of obseners'
improvements in counting birds in subsetjuent
years. Kendall et al. (1996) suggested that to
reduce Ist-time observer effects, Ist-yr data
could be eliminated fi'om antilyses, or the effects
might be reduced b\ improxed training of ob-
serxers prior to their 1st sm"X'ey. Because our
stiidx was of relatively short duration in com-
parison to the Breeding Bird Sun'ey, xvhich has
been unden\'a\' since the mid-1960s (Bobbins
et al. 1986, 1989), we are unable to eliminate

170

Great Basin Naturalist

[Volume 58

FiK- 1- Hflafivf locations of remote routes and latililN coinplix routes
1985-1991. Route designators relate to those in Table 1.

hn idiiii: bird census at the INEEL,

the 4 yr of data in wliieli Ist-tiiiie observers oniineiiclation of Kendall et al. (199(i). In otn-

perlbrnied the sui-\eys; instead, we made even' stnd\ all survey personnel were skillid with

effort to reduee potential iuterohserver and bird identilieation in the habitats ol interest,

Ist-time observer elleets nsin^ tlu> latter ree- they typieally had experienee in performing

1998]

Brkkdinc BiWD Cknsus at INEEL

171

standardized suneys for birds, and they were
roiitineK' trained in the point-count method
prior to l)eginniny; the sun e\ s.

Data AnaKses

Eaeh \ear, and for eaeh route, we reeorded
nunilier of birds ()l)ser\ed and iHnnl)er of
speeies deteeted (speeies rielniess). Beeause
the radius of surveys around stops was not
equal between t\pes of routes, we also trans-
formed bird abundanee and speeies data to
per-unit-area (km-) measures to allow more
appropriate eomparisons between types of
routes. Then, to assess differences in bird abun-
danee and speeies richness between txpes of
routes and among \ears, we performed 2-fac-
tor, repeated-measures ANOVAs (Winer et al.
1991) using the Statistical Analysis System
(SAS®, Version 6.1, SAS Institute', Can;' NC),
with t\pe of route as the between-group factor
and Near of suney (1985-1991) as the within-
subjects or repeated factor. We examined
assumptions (e.g., sphericit\") for repeated-
measures analyses using the REPEATED state-
ment in SAS prior to analysis and used Fisher's
protected least significant difference for means
comparisons at a rejection level (i.e., a) of 0.05.

We also examined relationships between
weather and climate \ariables and bird abun-
dance and species richness using the nonpara-
metric Spearman's correlation analysis (Sokal
and Rohlf 1995, conducted using SAS's CORK
procedure). Weather data were from the Na-
tional Oceanic and Atmospheric Administra-
tion monitoring station operated at the Cen-
tral Facilities Complex, which is located in the
southern portion of the stud\- area but rela-
ti\el\- centrally among the facilit\- complexes.
Although some variation in weather is likely
between the suney routes and this station,
and among suney routes, these data should
provide a general indication of weather condi-
tions at the site during each survey year. For
June 1985-1991, which is the month during
w hich most indixidual sun e\s were performed,
we calculated mean dail\ maximum tempera-
ture (all temperatures are reported as °C),
mean daiK minimum temperature, mean daily
temperature (i.e., dail\- maximum minus daiK
minimum and averaged across days of month),
maximum monthly temperature, minimum
monthK' temperature, and total monthl\- pre-
cipitation (cm).

Finally, to examine trends in populations of
sagebrush-obligate species, conunon shrub-
steppe species, and species of special concern,
using the REC procedure in SAS we regressed
against year (1) the total number of individuals
per route, and (2) number of individuals per
km^ sur\'e\ed for each of the 13 routes (see
Atkinson 1995). We included only those routes
for which the species of interest was detected
in >5 \n We subsequently (1) averaged regres-
sion coefficients to calculate trend means and
(2) determined the number of routes for which
regression coefficients were positive and
tested the observed distribution against a null
random distribution (e.g., that half of the coef-
ficients should be positi\e) using a X~ good-
ness-of-fit test (including Yates correction for
continuity, Zar 1996). We used this approach
rather than the route regression approach
used in more expanded studies of standardized
Breeding Bird Suney data because the major-
ity of routes in our study were not standard
BBS routes and the 7 yr of data from our study
would result in degrees of freedom below those
recommended for the latter (see Geissler and
Saner 1990).

Results

From 1985 through 1991, we recorded
25,597 individuals representing 90 species
along 13 suney routes (Tables 1, 2). Western
Meadowlarks (StiirncUa neglecta) were most
abundant; this species occurred along all 13
routes and at approximately 62% of the 4991
stops. Other common species were Brewer's
Sparrows {Spizella breweri). Sage Sparrows
{Amphispiza belli). Horned Larks {Eremophila
alpestris), and Sage Thrashers {Oreoscoptes
montanus), eaeh of which occurred at more
than 1100 stops and along all 13 routes (Table
2). These 5 species accounted for approxi-
mately 72% of all individuals over the study
period. Mourning Doves (Zenaida macroura),
I3row n-headed Cowbirds (Molothni.s atcr), and
Common Nighthawks (Chordeiles minor) also
occurred along each of the 13 routes but in
smaller numbers than the preceding species.
None of the other 82 species were recorded
along all 13 survey routes (Table 2). Yellow-
headed Blackbirds (Xanthocephalus xantho-
cephcdus) and Franklin's Gulls {Larus pipixcan)
also were relatively abundant, but these 2
species were present along fewer routes and

172

Cheat Basin Natlkalisi

[\'olunie 58

Table 2. Species and number of birds obscned alon'^ bird snr\t'\- rontes ()i = 13) at the Idaho National Plnuineering
and Environmental Laboraton, 1985-1991.

(hcrai!

.\unual

\alues

No.

Stops

Coniiiion name

Scientific name

No.

%

Routes''

Stops^'

%

{x±s)

ix+s)

Western Meadovvlark

Stumello neglecta

4497

17.6

5,8

2129

61.9

642 ± 275.6

,304 ± 84.4

Brewer's SpatTow

Spizella brewvri

4297

16.8

5.8

1711

49.7

614 ± 430.3

244 ±114.9

Sage Span-o\v

Amphispiza belli

3731

14.6

5,8

1830

53.2

533 ± 297.2

261 ±89.4

Homed Lark

Eremophila al))estris

3348

13.1

5.8

1195

.34.7

478 ± 123.6

171 ±36.9

Sage Thrasher

Oreoscoptes inontami.i

2441

9.5

5,8

1670

48.5

.349 ±91.8

2.39 ±61.8

Mouming Dove

Zenaida macroiiai

996

3.9

5,8

600

17.4

142 ± 64.4

86 ± 33.0

Brown-headed Cowbird

Molothrua alcr

875

3.4

5,8

427

12.4

125 + 59,4

61 ± 20.0

Yi'llow -lu'adcd Blackbird

Xanthoccphulus
xaiithocephalus

610

2.4

2,4

70

2.0

87 ± 67.5

10 ± 6.0

Franklin's Ciiill

Lurus pipixcan

495

1.9

1,4

16

0.5

71 ± 178.4

2 ±4.4

Common Nit;litha\\k''

Chordeiles minor

495

1.9

5,8

288

8.4

71 ± .30.6

41 ±16.2

Brewer's Blackbird

Euphagus cyanoccpliahis

375

1.5

4,8

143

4.2

.54 ± 22.9

20 ± 6.9

Killdeer

Charadrius vociferus

353

1.4

3.8

173

5.0

50 ± 16.5

25 ± 8.0

Vesper Sparrow

Pooecetes gramineus

308

1.2

5,7

151

4.4

44 ± 63.8

22 ± 28.5

Loggerhead Shrike

Lanius ludovicianus

280

1.1

5,7

210

6.1

40 ±18.7

30 ±10.9

European Starling

Sturmis vulgaris

186

0.7

1,8

57

1.7

27 ± 20.0

8 ±6.6

Wilsons Phalaropc

Steganopus tricolor

166

0.6

1.2

10

0.3

24 ± 35.4

1 ± 0.5

Black-billed Magpie

Pica pica

164

0.6

4,5

110

3.2

23 ± 12.6

16 ±7.2

Sage Grouse

Centrocercus uropluisianiis

163

0.6

5,5

34

1.0

23 ± 32.0

5 ± 4.6

Bam Swallow''

Hinindo rustica

152

0.6

2,8

70

2.0

22 ± 8.7

10 ± 3.9

Short-eared Owl

Asia flaimncus

144

0.6

5,7

91

2.6

21 ±.37.5

13 ±21.3

Ferruginous Hawk

Buteo rcgalis

95

0.4

5,5

7.3

2.1

14 ±3.3

10 ± 2.6

Bank Swallow-'

Riparia riparia

95

0.4

2,2

25

0.7

14 ±10.8

4 ±1.3

American Robin

Turdm migratoriiis

84

0.3

4,4

42

1.2

12 ±6.8

6 ±3.3

Canada (ioose

Branta canadensis

82

0.3

1,1

2

0.1

12 ± 26.8

<1

House Sparrow

Passer domesticus

79

0.3

0,1

10

0.3

11 ±16.2

1 ± 0.8

American Kestrel

Falco sparverius

72

0.3

4,6

53

1.5

10 ± 5.5

8 ±4.4

Red-tailed Hawk

Btiteo Jamaicensis

67

0.3

4,7

63

1.8

10 ±11.3

9 ±10.2

House Finch

Carpodacus mexicanus

67

0.3

0,6

20

0.6

10 ±9.6

3 ±1.9

Northern Harrier

Circus cyaneus

60

0.2

5,5

54

1.6

9 ±4.0

8 ± 4.0

CJommon Raven

Corvus corax

57

0.2

5,3

45

1.3

8 ±5.5

6 ±3.3

Lark Bunting

Calamospiza inrlauocon/s

49

0.2

1,2

17

0.5

7 ±16.8

2 ±5.6

Northern Shoveler

Anas chjpeata

48

0.2

0,2

15

0.4

7 ± 7.0

2 ±1.4

Lark Sparrow

Chondestes granuuarus

42

0.2

3,1

23

0.7

6 ±6.1

3 ± 2.9

CJommon Flicker

Colaptes auratus

40

0.2

3,0

3.3

1.0

6 ± 3.8

5 ± 2.9

Mallard

Anas platijrh ynchos

36

0.1

0,2

(i

0.2

5 ± 8.4

1 ± 0.9

Ruddy Duck

Oxyura jainaicrnsis

36

0.1

0,2

10

0.3

5 ±1.8

1 ± 0.5

Ciiuiamon Teal

Anas cyanoptera

33

0.1

0,2

S

0.2

5 ±6.8

1±1.1

(.'hipping Sparrow

Spizella passerina

33

0 1

1,0

13

0.4

5 ± 4.6

2 ±2.0

Rock Wren

Salpinctes ohsotetus

33

0,1

1,5

21

0.6

5 ± 6.7

3 ±3.6

American Avocet

Recurvirostra americuna

30

0.1

0.1

1

0.1

4 ±6.4

1±0.5

N. Rough-winged Swallow

Stelgidopteryx serripcnnis

:50

0.1

1.5

16

0.5

4 ±4.5

2 ±1.8

(iadwall

Anas streperu

2S

0.1

0,3

~

0.2

4 ± 6.2

1±1.5

Bluc-wingcd Teal

Anas discors

2(i

(1,1

0,2

6

0.2

4 ± 5.4

1±1.5

Swainson s Hawk"'

Buteo swainsoni

23

0,1

5,2

22

0.6

3± 1.4

3 ±1.4

La/uli Bunting

Passeiina ainocua

23

0,1

1,0

15

0.4

3 ± 5.2

2 ±3.4

Redhead

Aytliya colhiris

21

0,1

0,2

1

0,1

3 ±3.2

1 ± 0.5

Rock Dove

Coluniha lit iu

17

0,1

0.1

5

0.1

2 ±3.3

1±1.2

American Coot

Fulica atnerirana

1(>

0 1

0,2

9

o,:5

2±2.1

1 ± 1.0

Say's Rhoehc

Sayornis saya

l()

0.1

1,6

1 1

0.4

2 ±3.0

2 ± 2.9

Cray Flycatcher

Enipidonax wrightii

1 1

0.1

2,1

10

0.3

2 ±2.9

1±2.2

Burrowing Owl

Athene ennienlin-in

1.)

0,1

\:.\

12

0,3

2 ±3.1

2 ± 3,0

Northern Pintail

Anas aiiild

9

<0,1

0 1

2

0,1

1 ± 3.0

<1

Prairie I'alcon

I'ldeo inrxi((nius

9

<0,1

2,1

S

0.2

1 ±1.4

I ± 1.4

Cliil' Swallow"

I'elroelieliddn ptinlunuitii

9

<0,l

I.I

.■)

0,1

1 ±2.6

<1

Lesser Scaup

Aylliya ajjinis

S

<0.l

0.2

:\

0,1

1 ± 1.7

<1

Eastern Kingbird-'

Tyrannus lyrannus

8

<0.1

■1 ■■)

.5

0,1

1 ± 1.9

1 ± 1,1

Clark's Nutcracker

Xniifragfi cithtnthianu

8

<0.1

1,0

1

0(1

1 ± 3.0

<1

Red-winged Bhx klmd

Allildiiis ptuHiitirus

7

<().!

1.2

1

0,1

1 ± 1.5

1 ± 0.8

1998]

Bki.i.dinc Bii^i) (>b:NSis at INEEL

173

Tahii-; 2. CDiitiiiiii-il.

Overall

.Vnnual

\ alucs

\o.

Stops

Coinmoii naiiu-

Scientific naini'

No.

''(■

lioutes''

Stops'

^i

I.V ±.S)

f.v ±.V)

Xioli't-uiri'ii Swallow

iaclujcimta tluilassiiui

7

<().l

2.2

5

0.1

1 ± 1.8

1 ± 1.1

Rint;-hillrdC;iiil

l.dni.s (hlauarensis

(i

<().]

2,2

4

0.1

1 ± 0.9

1 ± O.S

("omiiion CiukU'iKVr

HuccphdUi clan<iula

6

<().!

1.1

2

0.1

1±1.9

<1

(Iieut HoiiKxl Owl

Bubo virfiiniaiius

6

<0.1

1.2

3

0,1

1 ± 1.5

<1

Wfsfcni Kiimliinl''

Tijraniiu.s vcrticali.s

6

<().]

2,1

5

0.1

1 ± 0.9

1 ± O.S

l\iiiu;-nctkr(i I'lu'asaiit

rliasiatius colchiciis

6

<().!

0.3

5

0.1

1 ± 1.5

1 ± 1.1

Willi-t

( (iloptropliorus
.'iCiniixiliiuitiis

5

<().!

1.1

5

0.1

1+0.8

1 ± O.S

CloniTiioii Poor-will

rhalainoptilus nuttnlii

5

<().!

1.0

4

0.1

1±1.9

1±1,5

Spotti'ci SandpipcT

Actiti.s inaciilaria

4

<().[

0.2

3

0.1

1±0.8

<1

Mountain Bliirliiicl

Sialia nimicoidcs

4

<().!

1.0

3

0.1

1±1.0

<1

Ciiav Partiitlt;i-

Pcrdix pcrilix

4

<().!

3,0

3

0.1

1 ± 1.1

<1

California Cull

Icarus cdlifornicus

3

<().!

2,0

3

0.1

<1

<1

Caspian Tern

Stenm caspiu

3

<().!

1,0

1

<0.1

<1

<1

Forster's Torn

Sterna finstcri

3

<().!

1,0

1

<().l

<1

<1

Louu-hilli'd (.'urifw

Xiimcuiiis aiiu'ricaiuis

3

<().l

1,0

2

0.1

<1

<1

Coick'u llaglc

Aiiuila chrij.sai'tos

3

<(),!

1,1

3

0.1

<1

<1

Blue Cira\' Gnatcafcher

Polioptila rai'nih'a

3

<().]

I.O

2

0.1

<1

<1

Creen-wingecl teal

Anas crccca

2

<().!

0,1

1

<().!

<1

<1

Wood Duck

Aix sponsa

2

<().l

0,1

1

<().l

<1

<1

W liite-taced Ibis

rlc<;adis chilli

2

<().!

1,0

1

<().!

<1

<1

Cooper s Hawk

Accipiter cooperii

2

<().!

1,0

2

0.1

<1

<1

Savannah Sparrow

Passercithts samlwirhcnsis

2

<().!

0,1

2

0.1

<1

<1

(ireen-tailed Towliee

Pipih) chlorunLs

2

<().!

1,0

•T

0.1

<1

<1

Eared Crebe

Podiceps n i<iricoHi.s

1

<().!

1,0

1

<().!

<1

<1

Sora

Porzana carolitia

1

<().!

0.1

1

<0.1

<1

<1

Greater Yellowlesis

Trintia tnclanolcuca

1

<().l

0,1

1

<().l

<1

<1

Merlin

Faico coluinhahiis

1

<().]

1.0

1

<0.1

<1

<1

Willow Flycatcher''

Euipidonax traiUii

1

<0.1

0.1

1

<0.1

<1

<1

American ("row

Coitus hrachyrhynrhDs

1

<().]

1.0

I

<0.1

<1

<1

Orchard Oriole'

Icterus spurius

1

<().]

1.0

1

<().!

<1

<1

Song Sparrow

Mc'lospiza mclodia

1

<().]

1.0

1

<0.1

<1

<1

Mountain Chickadei'

Poccilc uainhcU

1

<().]

1.0

1

<0.1

<1

<1

T. M\l

23.397

100. 0

Winters exclusively soiitli of the U.S. (aiter Dobkiii 1994).

Number of remote routes along which species occiiiTed, number of faciHt)' complex routes aloiiji; which species occuiTcd.
' .Number of stops at which species was detected; total stops surHned = 4991.

occurred at very few .stops along those routes
(Table 2). Many species observed within the
study area were neither widespread nor abun-
dant. For example, 2(S species (31.1%) occurred
along onl\- 1 of the 13 routes, and 39 species
(43.3%) were represented by fewer than 10
iiKli\ iduals (Table 2).

Comparisons Between
Types of Routes

There were no significant differences be-
tween remote routes and tacilit) complex routes
for the absolute number of indi\ iduals or species
(richness) obser\'ed (Table 3). However, both
average number of birds per km^ surveyed
and average number of species per km- were
significanth greater for facilitx complex routes

(Table 3). Thus, despite the fact that these
routes were shorter in length than remote
routes and that a smaller diameter around
each stop was censused, theie were more indi-
viduals and more species per imit area along
facility- complex routes.

.Species Assemblages

In addition to differences in densitx' of indi-
\iduals and the ninnbcr of species per km-,
the composition of species also differed be-
tween remote routes and facility complex
routes.

\\'aterF(JW L. — Of the 14 species of water-
fow 1 (order Anseriformes, family Anatidae) de-
tected along the surv^ey routes (Table 2), only 2
species (14%) were recorded along remote

174

Great Basin Natur.\ijst

[Volume 58

Table 3. Comparison of bird survey results between routes located near INEEL facility complex sites (n = 8) and
those in remote areas {n = 5). Means (± s^) of dependent \ariables and results of 2-factor repeated-measures ANOVA
are presented. Note: Year was a repeated factor in the analysis.

Facilit)' complex

routes

Remote routes

Variable

(x±*,)

{x±s^)

Fi.u

P

Birds recorded

240.6 ± 32.8

346.3 ±41.4

4.0

0.071

Avg. number of birds/km-''

103.7 ± 9.2

13.8 ±11.7

47.1

<0.()01

Species richness

16.4 ±1.3

17.3 ±1.7

0.2

0.692

Avg. number of species/km-

7.9 ±1.1

0.7 ±1.4

16.2

0.002

"Significant interaction between t\pe of route and vear for this variable; see Figure .3.

routes: Canada Goose {Branta canadensis) and
Common Goldeneye [Biicephala clanguhi).

Shorebirds, gulls, and WADERS. — Thir-
teen species of shorebirds/wading birds/gulls
and terns were observed (Table 2). Of these, 5
were observed along remote routes only, 3
species were observed along facility complex
routes only, and the remaining 5 occurred
along both types of route. The most abundant
species among these was Franklin s Gull, which
was observed along 4 of 8 facility complex
routes but only 1 remote route (Table 2).

Raptors. — Twelve species of raptors, in-
cluding eagles, falcons, hawks, and owls, were
observed along the survey routes. Although
most species of raptors were detected equally
along both types of routes, Swainson's Hawks
{Buteo sivainsoni) and Burrowing Owls {Athene
cunicularia) occurred along 80-100% of the
remote routes but only 25-38% of the facility
complex routes, respectively. Additionally,
Cooper's Hawks [Accipiter cooperii) and Mer-
lins (Falco coJumhariiis), both of which were
very rare, occurred along remote routes only
(Table 2).

Neotropical migrants. — The study re-
corded relatively few species of Neotropical
migrants (n = 9) that winter e.xclusivcK' south
of the U.S. (e.g., wintering areas 1-3 in Dobkin
1994; Table 2). Most of these were detected in
equal proportion along both remote and facil-
ity complex routes. The exceptions included
Swainson's Hawks, which occurred along more
remote routes; Orchard Orioles {Icterus spiirius),
which occupied remote routes only; and Wil-
low Flycatchers (Enif)i(l<>na.\ tniillii), wliicli
occurred along lacilit) complex routes onK.
The latter 2 species, however, each were rep-
resented by a single individual througliont the
study period, and thus were very rare.

E.XO'lIC AM) IRHAM/KD SPECIES. — I'UialK,

species associated with human introductions.

human-altered landscapes, or other human
activities typically occupied facility complex
routes rather than remote routes. European
Starlings {Sturnus vulgaris). Barn Swallows
{Hirundo nistica). House Sparrows {Passer
douiesticiis). House Finches {Carpodacus uiex-
icanus). Rock Doves {Colmnba livia), and
Ring-necked Pheasants {Phasianus colchicus)
either were not observed along remote routes
or occupied fewer remote routes than facility
complex routes (Table 2). However, a single
introduced species. Gray Partridge {Perdix
perdix), was observed along 3 remote routes
only.

Effects of Year

Mean number of birds per route differed sig-
nificantly among years (f (^ gf, = lfi.35, P <
0.001); the greatest numbers ol birds were
tallied during 1990 and 1989, respecti\'ely, and
the fewest birds occurred during 1988 (Fig.
2a). Average number of birds per km- also dif-
fered significantly among \ears (Fj.; (^(.; = 5.88,
P < 0.001), peakuig in 1989 (Fig. 2b), although
for this dependent variable year interacted
with type of route (see below). A\erage num-
ber of species per km- of sur\ey area {F^^fi^;, =
2.02, P = 0.075, Fig. 2c) and species richness
(Ffif^e = 2.13, P = 0.002, Fig. 2d) did not dif-
fer significantK among \ears. FinalK, the sig-
nificant interaction between type of route and
year lor birds per km- (F(^(^(^ = 3.34, P =
0.006) is apparently explained b\ ri'latixcK
larger increases in this \ariable along facilit\
comple.x routes in (lie latter Ncars of the studx
(iMg. 3), wliicli gcueralK' corri'spoiulcd witli
cooler and wetter weather (see below).

l{elati()iisliip to Wrallicr

Soiue xarialioH in bird abundance and di-
\c'rsif\ appeared to be iclated to wi-ather (Table
4). Tlie first 4 yr of the study (1985-1988)

1998]

Breeding Bird Census at INEEL

175

90 91

d.

21 ■

20-

19-

18-

~~-—

V >\

\ /\ r

17 -

\

/ \

IB-

\

/

^■~~~-

\

J

IS-

1

14-

13-

1?-

Fig. 2. (a) Number of breeding birds per route, 1985-1991, (b) number of birds per km^ of survey area, (c) number of
species observed per km^ of survey area, and (d) number of species observed (species richness) per route. A\\ values are
.r ± Sjr and n — 1.3. Means that differ significantK have different letters. Note: No means comparisons were performed
for number of species per km- or species richness because the ANOV'A was not significant at the 0.0.5 level.

tended to be warmer and drier, while the sum-
mers of 1989-1991 were cooler and wetter.
Bird abundance (mean birds/route and mean
birds/km^) was significantly correlated with
a\'erage temperature, average minimum tem-
perature, average maximum temperature, and
total precipitation; that is, more birds were
recorded when temperatures were lower and
when precipitation was greater (Table 4). There
was no relationship between bird abundance
and absolute minimum and niciximum temper-
atures for June during the study period (Table
4). Moreover, there were no relationships de-
tected between average species richness or
species per km- and an\' weather variables
measured (Table 4).

Population Status and Trends
for Selected Species

Sagebrush obligates. — Of sagebrush-obli-
gate species, both Brewer's Sparrows and Sage
Sparrows exhibited significant positive trends
in abundance (Tables 5, 6). Brewer's Sparrows
exhibited positive regression coefficients across
all 13 routes (5 of the individual regression
analyses were significant at the 0.05 level or
less), suggesting that this species increased
along both remote and facilit\' complex routes.
SimilarK; Sage SpaiTows had positive regression
coefficients for all but 1 route (a facihty complex
route: Radioactive Waste Management Com-
plex), but fewer individual regressions were

176

Great Basin Natihalist

[\bluine 58

Remote
Facility Complex

H

85 86 87 88 89

Fig. 3. Relationship lietwecn type of route (remote,
facilit\ complex) and \ear of sunex', which interacted sig-
nificanth; for the dependent variable number of birds per
km-. Means (± .Sj) for remote routes (ii = 5) and facilit\-
comple.x routes {n — 8) are illustrated.

significant (Table 6). Sage Thrashers, while com-
mon along all routes, increased along some
and decreased along others (Tables 5, 6), and
there was no consistent pattern between types
of route (remote routes: 3 positive, 2 negative;
facility complex routes: 4 positive, 4 negative).
Sage Grouse {Centrocercus urophasianus), also
sagebrush obligates, were relatively common
within the study area (Table 5); however, no
trend mean could be calculated because Sage
Grouse were not detected in >5 yv along an>'
single route.

OlilER SUKl BS'IEPPEA-RASSEAM) SFKCIKS. —

Among other common shrubstcppe species
(Table 5), Western Meadowlarks, Homed Larks,
Mourning Doves, and Vesper Sparrows {Pooc-
cetcs <i,r(iiniiu'us} had more routes with posi-
tive than negative regression coefficients and
positive trend means, indicating that these
species tended to increase in al)undance rather
than decline (Table 6). However, lor none of
these species was the goodness-ol-iit test sig-
nificant, but expected cell frc(|uencics were
low in at least some cases (e.g., for Vesper Spar-
rows that produced only 3 regression coclli-
cients). Brouii-hcadcd Gowbirds and Goninion
Nighlhawks had more routes uilh negatixc re-
gression coellicients and negalixc trend means,
indicating that these species tended to decline
in abundance oxer the study jieriod (Tables .1,
(■)). Of the 10 rontes lor which cowbirds had
negative coefficients, 4 were remote rontes and

6 facilit\ complex routes. Only Kyle Can\on,
Idaho CJieiuical Processing Plant, and fladio-
acti\ e Waste Nhmagement Complex routes had
coefficients greater than zero. For nighthawks,
1 lemote route (Twin Buttes) and 1 facilit} com-
plex route (I^adioactixe Waste Management
Gomplex) had positixe regression coefficients,
while the remainder of routes in = 6) exhib-
ited negative regression coefficients (Table 6).
Species of special concern. — No avian
species listed as threatened or endangered b\'
the U.S. Fish and Wildlife Ser\ice were ob-
served, but the following species of special
concern (Mosely and Groves 1994) occurred
along the routes: Ferruginous Hawks {Biiteo
regali.s). Burrowing Owls, Loggerhead Shrikes
{Laniits liidovicianus). White-faced Ibis {Ple-
gadis chilli), and Long-billed Curlews {Nwne-
niiis americanus). The stud\- recorded an aver-
age of 14 Ferruginous Hawks per >ear, and
this species occupied all 5 remote routes and 5
of the facility complex routes (Tables 2, 5).
Only 3 routes (all remote routes) proxided suf-
ficient data for analysis of trends for Ferrugi-
nous Hawks, and all 3 had regression coeffi-
cients less than zero, and 1 of these (Kyle
Canyon route, P = 0.01), was significantK dif-
ferent from zero (Table 6). Burrowing Owls
also occupied both types of routes but were
much less abundant than Ferruginous Hawks
(Table 5). A trend anabsis could not be per-
formed for Biurow'ing Owls because the\' were
not detected along any single route for >5 \r.
Although Loggerhead Shrikes occupied 12 of
13 routes (Tables 2, 5), onK 7 routes pro\ided
sufficient data for trend anaKsis (Table 6). Of
these routes, 3 had positixe and 4 had nega-
tive coefficients, and the trend mean for Log-
gerhead Shiikes was negatixe (Table 6). Finallx,
White-faced Ibis (n = 1) and Long-bilh>d
Curlexvs (/i = 3) xx'ere rare and occnned along
remote routes only (Table 2), bnt no ti'end
analx sis eonid he perlornied loi" eitliei' species.

Disc rssioN

Willi respect (o a\i(aniia, low species rieli-
ness is t\ pical oi aiicl and seniiarid slniib-
steppe and grassland habitats thronghont the
wesleni I niled States (e.g., W'iens and lioten-
l)err\ 19S1. W iens 19S5. Dohkiu 1994). Nhnc--
()\er, these liahilats snpjiort iclatixclx lew
Neotroiucal migrants x\ Ikmi compared to ripar-
ian or forested habitats in the same regions.

1998] Bhki;i)i\(. BikdCknsus ATlNEEL 177

I'MUI: 1. WcatliiT and iliinatc data lor tlir iiidiiUi oI June and llicir rclalionsliip to Inrd ahundanic and richness at tlie
I NMl'^L. UiS.'j-Ujyi. All tt'inperatiiR's arc °C, aiul pivcipitatioii is rcporti-cl in cm. Hclationships hchvccn weather variables
and bird abiiiidaiicc and species ricliness arc indicated by a correlation niatri.x sliowinji Speaniian correlation coellicieiits
w ith associated P-%alncs.

Mean

Mean

Year

Mean temp.

min. temp.

ma.\. temp.

M,

ax. ti'm[).

Min. temp.

Total prcci]).

1985

17.0

7.6

26.4

33.9

1.7

1.0

1986

IS.O

7.8

28.3

34.4

2.2

1.6

1987

17.1

7.2

27.0

33.3

-2.2

1.9

1988

19.6

8.8

30.2

37.8

0.0

0.3

1989

15.1

5.3

25.0

32.2

-3.3

3.1

1990

16.2

6.4

26.0

36.7

-1.1

2.2

1991

1.5.6

6.7

Spearman

24.6
Correlation C'oe
(/^-\alue)

Hicients

30.0

0.0

2.9

Mean l)irds/roiite

-0.79

-0.82

-0.75

-0.28

-0.29

0.78

(0.036)

(0.023)

(0.052)

(0.534)

(0.531)

(0.036)

Mean birds, km-

-0.86

-0.86

-0.78

-0.43

-0.36

0.86

(0.014)

(0.014)

(0.036)

(0.337)

(0.427)

(0.014)

Mean species ronte

-0.21

-0.04

-0.14

0.0

0.49

-0.04

(0.644)

(0.939)

(0.760)

(1.0)

(0.268)

(0.939)

Mean specics/kni-

-0.23

0.04

-0.23

-0.20

0.61

-0.02

i().613i

10.9:39)

(0.613)

(0.670)

(0.147)

(0.969)

IaBLL; 5. Mean (± s) numlier ol l)irds per route for sagebrush-obligate species, other common shrubsteppe species,
and species of special concern at the INEEL, 198.5—1991. Nimiber of sune\ routes along wliich species was recorded is
indicated in parentheses. For results of trend anaKses, see Table 6.

Year

Species 1985 19S6 iyS7 19.S,S 1989 1990 1991

S.u;i:bri sii ()ii!,i(;\ii;s

Brewer's Sparrow 9.6 ± 7.7 45.0 ±20.1 27.2 ± 12.2 15.4 ± 14.3 74.7 ± 32.2 99.5 ± 66.9 60.3 ± 37.0

(13) (13) (13) (12) (13) (1.3) (13)

Sage Sparrow 44.6 ± 20.3 19.5 ± 12.8 18.5 ± 13.0 35.5 ±20.1 25.5 ± 18.0 72.2 ±39.4 71.2 ±38.6

(13) (13) (13) (13) (13) (1.3) (13)

Sage Thra.sher 26.9 ± 15.3 35.8 ±17.6 22.5 ±9.5 15.8 ±6.3 22.7 ±14.7 34.2 ±23.0 29.8 ±16.6

(13) (13) (13) (13) (13) (1.3) (13)

Sage Grouse 1.6 ±1.1 5.0 ±1.4 8.0 ±9.0 12.8 ±26.6 0 5.2 ±3.4 0

(3) (2) (4) (7) (0) (5) (0)

Other common shribsteppe species

Western Meadowlark 41.1 ±23.2 .52.5 ± 20.9 .30.8 ± 16.8 21.5 ±12.0 85.6 ±37.8 62.6 ±35.4 51.8 ±24.4

(13) (13) (13) (13) (13) (13) (13)

Horned Lark 30.1 ±.32.2 .32.4 ± 43.6 45.4 ± 42.9 25.0 ±27.0 38.6 ±44.4 39.5 ±48.7 52.1 ±61.6

(13) (12) (13) (13) (13) (12) (13)

Mourning Dove 8.1 ±6.0 8.6 ± 8.2 14.5 ±1.5.0 7.5 ±5.7 16.5 ±1.5.7 18.6 ± 19.6 9.5 ±7.4

(12) (12) (11) (10) (13) (13) (11)

Brown-headed C^owbird

19.8 ± 24.3

10.6 ±7.7

13.9 ±11.1

6.4 ±7.8

9.7 ± ,5.8

7.0 ± 6.7

4.8 ± 2.5

(11)

(13)

(13)

(11)

(1.3)

(12)

(12)

( 'onunon Nightliawk

10.4 ±8.3

6.0 ± 5.9

5.7 ± 2.4

11.8 ±8.2

4.8 ± 5.6

9.8 ±11.2

4.9 ± 3.6

(8)

(11)

(9)

(11)

(9)

(8)

(9)

N'esper Sparrow

1.8 ±1.8

2.0 ±1.0

4.5 ± 4.9

7.0 ±7.1

8.3 ± 7.9

4.0 ±1.4

24.4 ± 25.4

(5)

(3)

(2)

(2)

(11)

(4)

(7)

Species of speci.m. concern

Ferruginous Hawk

2.8 ± 3.0

3.2 ± 3.3

3.6 ± 2.6

3.5 ±2.1

2.8 ±1.5

2.8 ±1.7

2.0 ±2.0

(5)

(5)

(5)

(4)

(5)

(4)

(4)

Loggerhead Shrike

5.9 ±3.0

5.3 ± 4.0

.5.9 ± 5.4

2.6 ±2.6

2.4 ±1.5

5.2 ± 5.5

3.5 ±1.9

(11)

(9)

(9)

(5)

(8)

(9)

(10)

Burrowing ()w 1

1.3 ± 0.5

4.0

0

0

1.0

0

0

(6)

(1)

(0)

(0)

(1)

(0)

(0)

178

Great Basin Naturalist

[\blunie 58

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1998]

Brkkdixc Birh Census at INEEL

179

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180

Great Basin Natl fl\list

[\blunu' 58

For example, altlioiitili more than 50 speeies of
Neotropical migrants ma\' breed in various
parts of the Intermountain West shruhsteppe,
the topical eommimit) lias 2-7 rej^uiar breed-
ers, with 100-600 birds/km^, and oxer half of
all individuals belong to the most conmion
species (Bock et al. 1993). Results from our
study indicate that richness and density of
birds at the INEEL are relatively low as well,
as each route supported an average of 13-22
species and 11-169 indi\'iduals/km- for the 7
yr of the study. Although 90 different species
were recorded, the 5 most abundant species
accounted for 72% of all individuals, and over
40% of all species were represented by fewer
than 10 individuals. Despite the low number
of species, the INEEL does provide important
habitat for several species that depend largely
on sagebmsh communities (e.g.. Brewer's Spar-
rows, Sage Sparrows, Sage Thrashers, Sage
Grouse), some of which have experienced de-
clines in many portions of their range (Dobkin
1994).

IdealK. to assess the significance of trends
in population numbers, one should have data
from many years, over which biases related to
effects of short-temi variation can be minimized
oi' eliminated. Because the current stud\ was
of relatively short duration, the trends in abun-
dance we calculated for each species could be
adversely affected by such variation. With this
caveat in mind, it appears that none of the
common species we examined declined signif-
icantly in abundance during the study period.
In contrast. Brewer's Sparrows and Sage Spar-
rows appaix'utly increased significantK in abun-
dance during the years of the study. These
increases foi- Brewer's and Sage Sparrows are
in contrast to statewide and regional trends.
Based on icgioiial anaKses of BBS data and
other published information, Dobkin (1994)
concluded that Sage Sparrow numbers declined
in Idaho (i)ut sample sizes were very small)
and that Brewer's Sparrow mmibers haxc
declined steepK' and significantK' in Idaho.
Declines in sagebrush-obligate species are
likely related to widespread loss or Iragnienta-
tion of sagebrush habitat that has oceuncd
throughout much of the West. 'I'his habitat is
being converted to grasslands \ ia lire followed
by invasion of nonuatixc, annual grass species
(Billings 199 1, Peters and Unnling 1994), or it
is being converted to agiiciilture. Knic-k and
Hotenberry (1995) determined that site occu-

pancy by shrubsteppe species (e.g.. Sage and
Brewer's Sparrows, and Sage Thrashers) in
southwestern Idaho was more probable with
larger shrub habitat patches and greater total
shrub cover, and b\ decreasing disturbance.
Sagebrush-obligate species ma\' be faring better
on the INEEL because large expanses of rela-
tively undisturbed sagebrush habitat remain.

There were significantK' more species of
birds and individuals per unit area along the
facility complex routes. This likeK reflects the
different types of himian activities along these
routes. For example, in addition to native shrub
habitat, some facility complex sites have man-
made ponds while others support a variety of
man-made structures, roads, and parking lots.
These different land-use patterns appear to
attract more species in greater density- than
habitats along remote routes. Remote routes
traverse large expanses of mostK undistinbed
habitat located in remote regions of the site.
Moreover, the collection of remote routes is
more homogeneous than facilitv' complex routes
(i.e., remote routes lack human structures and
there is little wetland habitat along each), and
this is reflected b\' the fact that bird abun-
dance and species measures varied less for
remote routes. In addition to increased varia-
tion in bird abundance along facility complex
routes, species composition differed between
remote routes and facility complex routes in
several important respects. Facilitv conipK'x
routes supported more species of waterfowl
and a larger number of "human-associated
species, while several species of raptors
(Ferruginous Hawk, Burrowing Owl, Gooper s
Hawk, Merlin, and Svvainsons Hawk) occurred
more conunonlv along remote routes. Such
data make it clear that human activity associ-
ated with construction and operation of major
facilitv com])le\es (buildings, roads, parking
lots, sewage ponds, etc.) on the INI'' I'll, site
aff(>ets the composition of a\ ilauua in compari-
son to remote sites, although facilitv eomi-jfex
aieas appear to supjioit greater numbers ol
indiv iduals.

Shrul)ste|)pe bird popnlations ean llnetuate
independeutlv ol one another and ol variation
in habitat structm-c> (Wiens c>t al. I9S6, Boek el
al. 1993), but then' appi'ais to be some assoei-
ation bi'tween bii'd abnndanee and |ilanl
species, tlieii' si-ed crops, and perhaps inseet
lanua ((^oebi'I and Berrv 1976, Wiens and
Rotenberrv I98I). However, Bock et al. (1993)

1998]

Bki:ki)i\{. Biki) Census at INEEL

181

conclude tluit (.'xtrenie and inx^unlar nuctiia-
tion in piccipilation and ccosx stem productiN-
it\ ina\ he [\\v priniai\ lactoi' inilucMicing
shiuhsti'ppe a\ iiauna. \\ liile sonii' short-term,
landom lluetuations in ai)undanee and \ariet\
ol axilanna eertainh' are expected, results of
correlation anahses suggest that some \ai"ia-
tion ohseixed in die present study was rt'lated
to weather conditions. For example, in warmer
and drier yinus ( 19(S5-198(S), fewer indi\ iduals
ol each species were detected, although there
was no such rt'Iationship for species richness.
One possible explanation for this pattern is that
detectahilitx ol hirds changed with weather
conditions. Birds ma\ lunc limited their singing
Ol' other actixities during hot, dr\ periods,
making them more difficult to census accu-
ratcK using the protocol empUnt'd. However,
the present study avoided at least some diffi-
culties along these lines by performing sur-
\ eys early in the day, when temperatures were
more moderate. Comersely, fewer birds ma\'
ha\c inhabited the stuck' area or attempted re-
production during hotter, drier years. If shrub-
steppe species are as highlv' opportunistic and
ecologicalK adaptable as Bock et al. (1993)
suggest, then more indi\iduals would appear
and attempt breeding during cooler years
w hen precipitation is high, and when summer
conditions are more favorable for reproduc-
tion (e.g., more plant cover and food, sununer
temperatures are less extreme). Interestingly,
the significant interaction between type of
route and Near of study for indi\iduals per unit
area suggests that larger increases in bird den-
sity in cooler, moister years were obser\ed
along facilitN routes. While an explanation of
this relationship is not obvious, fluctuations in
axifauna were more pronounced in habitats
that experienced more cHsturbance (i.e., along
iacilit>' complex routes). Finally, because there
was no relationship between species richness
and weather, it appears that most of the
weather-related \ariation among \ears was
reflected in changes in numbers of indi\ iduals
rather than in numbers of species.

Fi\e species of special concern (Mosely and
GroN'cs 1994) were detected along the survey-
routes. Of these, Loggerhead Shrikes and Fer-
njginous Hawks were relatively common, while
Burrowing Owls, White-faced Ibis, and Long-
liilled Curlew s were rare. PreviousK' published
studies indicate that Ferruginous Hawks have
declined somewhat in Idaho but increased in

nearb\ Montana, Loggerhead Shrikes have
maintained somewhat stable populations de-
spite large annual variation. Burrowing Owls
luiNc declined steadih' throughout their range,
and Long-billed (>urlew populations ha\'e re-
inained stable or undergone slight declines
(l)obkin 1994j. FinalK, White-faced Ibis pop-
ulations appear to be increasing in abundance
throughout many portions of their range (Saner
et al. 1997, internet access at littp://www.im.
nbs.g()\'/bbs). The 2 species for which we had
adec|uate data. Ferruginous Hawks and Log-
gerhead Shrikes, had negative trend means,
although the trends were not statisticalK sig-
nilicanl. Nonetheless, negatixe trend means
indicate possible declines, and more specific
studies diiectc-d at these species and the land-
management practices that affect them within
the INEEL boundaries and elsewhere may be
warranted.

In summary, the present stucK has pro\ ided
bird population data from shrubsteppe habi-
tats located at the Idaho National Engineering
and Environmental Laboratoiy which will be
useful for comparison with other studies in the
region and future studies at the site. Analyses
indicated that there are differences in avifauna
between remote areas and those located near
research facilities resulting from human-con-
structed ponds and structures and a variety of
human activities. Two common shrubsteppe
species (Brewer's Sparrows and Sage SpaiTows)
appear to have increased in abundance at the
INEEL during the stucK' period despite state-
wide and regional declines purportedK' from
destruction of sagebrush habitat. In addition
to proN'iding important large patches of habitat
for a number of sagebrush-obligate species,
the INEEL supported at least 5 a\ian species
of special concern, 2 of which had negative
trend means and declined in abundance along
some routes.

Ackx()\vled(;me.\ts

We thank J. Beals, R. Brooks, D. Drahn,
M. Munts, D. Snethen, L. Thoipe, M. Wheeler,
and several Associated Western Universities
field assistants for assistance in the field or wdth
data entry and management, and D. Dobkin,
A. Duft\, Jr., D. Thurber, and R. Whitmore for
helpful comments on a previous version of the
manuscript. We also thank Randy Lee, LM IT-
CO Environmental Assessment Technologies,

182

Great Basin Naturalist

[Volume 58

for drafting Figure 1. Financial and logistic
support was provided by the Environmental
Science and Research Foundation, the U.S.
Department of Energy, Boise State University,
and Northwest Nazarene College.

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Anderson, J.E., K.T Ruppel, J.M. Glennon, K.E. Holte,
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Foundation Report Series 005. Environmental Science
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ASKINS, R.A., J.E Lynch, .\\d R. Greenberg. 1990. Popu-
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Atkinson, E.G. 1995. Northern Shrikes (Lanius excubitor)
wintering in North America: a Ghristmas bird count
analysis of trends, cycles, and interspecific interac-
tions. Proceedings of the Western Foundation of Ver-
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Billings, W.D. 1994. Ecological impacts of cheatgrass and
resultant fire on ecosystems in the western Great
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BocK, C.E., VA. S.A^B. TD. Ric:h, and D.S. Dobkin. 1993.
Effects of livestock grazing on Neotropical migratoiy
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DoBKIN, D.S. 1994. Consei-vation and management of
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Great Plains. University of Idaho Press, Moscow.
220 pp.

FiNGll, D.M., AND PW. StaN(;el, EDrroRS. 1993. Status
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Department of Agriculture, Forest Service General
Technical Report RM-229. Rocky Mountain Forest
and Range E.xperiment Station, Fort C^ollins, CO.
422 pp.

GeISSLER, ph., and J.R. SaUER. 1990. ibpics in route
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U.S. Fish and Wildlife Service Hiological iU-i)ort 90.

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grass seeds by local birds. Journal of l^aTige Manage-
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population trends: 1966-1993. -■American Midland
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Kendall, W.L., B.C. Peterjohn, and J.R. Saler. 1996.
First-time observer effects in the North .American
Breeding Bird Sur\'e\'. Auk 113:82.3-829.

Knigk, S.T., AND J.T. ROTENBERRY. 1995. Landscape char-
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1059-1071.

MosELY, R., AND C. Gro\ Es. 1994. Rare, threatened, and
endangered plants and animals of Idalio. Conservation
Data Center, Idaho Department of Fish and Game,
Boise.

Pak;E, L.C. 1990. Population trends of songbirds in west-
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Peters, E.F, and S.C. Bunting. 1994. Fire conditions pre-
and postoccurrence of annual grasses on the Snake
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Kitchen, editors. Proceedings — ecology and manage-
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INT-GTR-313. Intermountain Research Station.
Ogden, UT

Reynolds, T.D., J.W Connelly, D.K. Halford, and W. J.
Arthur. 1986. Vertebrate fiuma of Idaho National
Environmental Park. Great Basin N'atmalist 46:
513-527.

Bobbins, C.S., D. Bystr.\k, and PH. Geissler. 1986. The
Breeding Bird Suney: its first fifteen years, 1965-
1979. U.S. Fish and Wildlife Serxice, Resource Pub-
lication 157. 196 pp.

Bobbins, C.S., J.R. Sauer, R.S. Greenberg, and S.
Droege. 1989. Population declines in .North Ameri-
can birds that migrate to the Neotropics. Proceed-
ings of the National .\cademy of Science, US.\
86:7658-7662.

Sauer, J.R., and S. Droege, editors. 1990. Survey
designs and statistical methods for the I'stimation of
avian population trends. U.S. Fish and Wildlife Ser-
vice Biological Report 90. 166 pp.

Sauer, J.R., and S. Droege. 1992. Geographic patterns in
population trends of NeotroiMcal migrants in North
America. Pages 2(i-42 in J.M. Hagan HI and D.W.
Johnston, editors. Ecology and consenation of Neo-
tropical migrant landbirds. Smithsonian Institution
Press, Washington, D(;.

Sauer. J.R., B.C. Peierjohn. wd W.A. Link. 1994.
Obser\er differences in the North Vnicrican Hmii-
ing Bird Sur\e\. .\uk 111:50-62.

Sauer, J.R., J.E. Hines, G. Cough, I. Thomas, and KX..
Pk'IERJohn. 1997. The North American Breeding i^iid
Survev results and anahsis. Version 96.3. I'.itnxenI
Wildlife Ri-search Center, Laurel, MD.

SnoHi. ILL. 1986. Rangelands. Pages 93-122 in A.Y.
( 'oopri rider, ILJ. Boyil, and H.IL Stuart, editors.
In\cnt()r\ and Tuonitoring of uildlile habitat. I'.S.
Department oi Interior. Bureau ol Lanil Manage-
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S<)K.\L, R.H., AND FJ. RoHLK 1995. iii()ni(tr\: the [irinci-
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3rd I'dition. W.IL Frei'UKm and CompauN, New York.
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1998] Breedinc BihdCknsus atINEEL 183

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ments: shriibsteppe birds. Pa^es 227-251 iii M.L. tistical principles in experimental design. 3rd edi-

Cody, editor. Habitat selection in I)ir(ls. .\caclciiiic tion. McCraw-Hill, Inc., New York.

Press, Inc., New York. /-^H. .1- •'• '996. Biostatistical analysis. 3rd edition. Pren-

WlKNS, J.A., WD J.T. RoTKNBF.RKV. UJSl. Haiiitat associa- ticc Hall, I'pper Saddle Hiver. NJ. 662 pp.

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W iKNS, J.A., J.T. RoTi-NBK RHV, AM) B. \'an Hornk. 1986. A Accepted 5 August 1997

lesson in the limitations of field experiments: shnib-
steppe birds and habitat alteration. Ecology 67:
365-376.

Great Basin Naturalist 58(2), © 199S, pp. 184-187

MITE PARASITISM OF MOSQUITOES IN CENTRAL WYOMING

Margo Frost Spurrier'

Abstuvct. — Parasitic lanal mites iiieliidiiig Thyasidcs sph(i<inorum were eollected from nK)S()iiit()es captured in New
Jersey light traps over a period ot 6 yr and from landings dining 1 collecting season in Natrona Count)'. Wyoming. 0\erall
mite prevalence on mosquitoes was 0.42% and ahimdancc was 0.76%. Prc\alence on Aecles clor.salis was significantU'
greater than on other host species. Comparison of light trap data and landing data suggests that parasitized mosquitoes
may seek blood meals more frequently than non-parasitized mosquitoes.

Kcij words: Hijiliarlntidia. Tin asides sphagnonmi, Aedes dorsalis, water mites, prevalence, mosquito parasitism.

As scientific information has revealed envi-
ronmental and health consequences of chemi-
cal control of mosquitoes, natural control of
mosquitoes has become an ongoing area of
study. Mosquitofish, Gambima ajfinis, and bac-
terial agents, such as Bacillus tJiitrin^fiensis var
israelensis and Bacillus s))J}aericus, have been
developed and are widely applied to control
mosquito larvae.

Larval water mites of the group Hydrachni-
dia (order Acariformes) are parasitic on aquatic
insects, including mosquitoes (Smith 1988). In
a review of all known records of mosquitoes
parasitized by mites, both Aedes dorsalis and
Culiscta inornaia are listed as hosts for mites
whose identities have not been determined.
Culex tarsalis has been parasitized by Fiona
sp. (Mullen 1975). Tsai et al. (1969) collected
ectoparasitic red larval mites {Arrenurus spp.)
from Ae. iticrcpitus, Ae. pullatus, and Cs. iinpa-
tiens in southwestern Wyoming.

Smith and Mclver (1984) noted that host-
seeking Coquillcttidia periurhans consistenth'
had a lower abundance and prevalence of par-
asitic mites than newly emerged ni()S(|iiit()es.
It also appeared that the abundance of iarxal
mites did not closeK' match the abundance of
available hosts.

This study was conducted to investigate the
prevalence and abundance of lan'al water mites
on different species of female moscjuitoes col-
lected in Natrona C^ountx, Wyoming, to deter-
mine the potential for utilizing mites for mos-
(jnito contn)!. .Mite prevalence, abundance,
and mean intensity (Margolis et al. 1982) wen-

investigated for C.v. tarsalis, Cs. inornaia, and
the genus Aedes. Seasonal and \ earK' patterns
were compared. Additional comparisons were
made between data collected from light traps
and data collected from mosquito landings on
human subjects.

Methods

Mosquitoes were trapped e\er\ night from
the 1st week of June through the middle of
September 1991-1996 in 5 New Jerse\ light
traps at 4 locations in Natrona Countv: Casper
(106°16'53"W, 42°50'05"N), Evansville (106°
15'58"W, 42°51'52"N), Vista West II (106°
26';30"W, 42°5r52"N), and Natrona Countx'
Airport (106°27'54"W, 42°53'35"N and 106°
27'24"W, 42°54'0"N) where 2 traps were
located. The E\ans\ille and Casper traps w ere
located in residential aieas. The \'ista West II
trap, which was in a riual irrigated subdi\ i-
sion, was not included in the 1991 stucK. One
airport trap was placed ne.xt to an irrigation
pond and irrigated jiastiue. the other ne.xt to a
ser\ ice building with no irrigation acti\it\ on
the gionnds sinroimding the building. Mos-
(|uitoes were collecti'd lioni the tiaps e\er\
Mondax, \\'ednesda\, and fVidax and wt'rt'
sorted by sex. No male moscjuitoi's were in-
chuk'd in the stuck. Female C.v. tarsalis and
Cs. inornaia wert> identified to species and
counted. I)ne to time constraints and dilli-
cnlt\ identibing some specimens to species,
leniale nienibcrs ol the nioscinito genus .Xcdcs
were gionpcd lor counting pniposcs. female

'CJaspiT-NutroiKiCli.unlv llcillli l)i|i.iitiiunl. 1200 KasI Tliiid Sliicl. Casper. UV S2()0I.

184

1998] Mm. I'akasiiism oiMosQUiTOES 185

Tahi.I-; 1. {.'()ml)iTR'(l ri'Milts Iroin 5 traps n-conk'cl from tlu- 1st wi'ck ol Jiiiu' tliroiitih niid-ScpffnibcT 1991-1996.

NiimlKT

M()S(jiiito

of 9

Nuiiiher ol

N

limber

Mite

Mite

specics/moup

nu)S(|iiitoes

$ hosts

ol

r mites

prexalence

abimdance

Aedes

.■5(i..514

240

434

0.66%

1.19%

Ciih'X tarsdii.s

Ifi.Sfil

7

8

0.04%

0.05%

CitliM'ta iiinnwta

<S,35fi

10

30

0.12%

0.36%

Total

61,731

2.57

472

0.42%

0.76%

ni()S(iuit()C'S with mites were separated and the
parasite load noted. All female host mosc^ui-
toes were identified to species, including Aedes.
Other species ofinosciuitoes in Natrona Count)
are not numerous enough to he included in
the stud). Collections ceased the 2nd full week
of September when the weather became too
cold for moscjuito acti\ it\.

AdditionalK; in 1996 mos(|uitoes were col-
lected in a New Jerse\ light trap and during
landings at another location in the county
(1()6°16'47"N, 42°52'51"VV). Landings were
conducted the day following a trap night dur-
ing which it was likeK" that parasitized mos-
(luitoes would be captured. A Hausherr mos-
cjuito \ acuum collector was used by a human
subject to gather mosquitoes landing on his
skin and clothing.

Statistical software in Epi Info Version 5
was used to anaKze mite prexalence on mos-
(juitoes landing on individuals versus those
collected in the New Jerse\' light trap. This
stuck was conducted in conjunction with the
routine mosquito surveillance program of the
Cit>- of Casper-Natrona Count)' Health Depart-
ment.

Results

Table 1 summarizes results for 1991-1996.
Aedes dorsalis, Cx. tarsalis, and Cs. inomata are
the 3 most abundant species of mos(|uitoes in
Natrona Count). Within the Aedes genus Ae.
dorsalis is most abundant, comprising approxi-
mately 90-957f of this group in Natrona
County (unpublished data). For Aedes the only
species found to be parasitized was Ae. dor-
salis. Mean parasitic intensities for tlie 3 groups
were Aedes, 1.81; Cx. tarsalis, 1.14; and Cs.
inomata, 3.00. Mite intensity varied from 1 to
as man)' as 9 mites per host. Cs. inomata had
the greatest mean intensit)' and is the largest
mosquito in size. No other species of mosqui-

toes were parasitized b)' mites. Larval mites
were observed attached to male mosquitoes
when sorting collections, but these were not
included in the stud)'.

T\\ o Ian al mites collected from Ae. dorsalis
were identified as Thyasides sphaii,norum by
Bruce E Smith. Mites were most commonly
found attached to the posteroventral region of
the thora.\ near the junction of the abdomen
(89%), followed by attachment at the neck
region.

For each )'ear of the stud)' both mite preva-
lence and mite abundance were greatest on
Aedes spp. Although all Aedes species were
grouped for counting purposes, only Ae. dor-
salis were found to be parasitized by mites;
therefore, actual prevalence and abundance
figures for Ae. dorsalis are somewhat greater
than indicated in Table 1. Statistical analysis of
host selection demonstrated significantl) higher
parasitism b\ mites on Ae. dorsalis (X" =
76.69, F < 0.0001).

Oxer the 6 yr of the study, mites were col-
lected from mosquitoes as early as 20 May and
as late as 18 September However, parasitism
by mites tended to occur over a 2-mo period
each summer, with the time of onset vaiying
from late May to Jul). Overall, 50% of the
mites were recovered during June; however,
in 1993, when the smallest number (17) of
mites was collected, 70% (12) of those were
found on mosquitoes in August. Mite speci-
mens collected early each year tended to be
engorged, whereas those collected later in the
season tended to be smaller and not engorged.

Prevalence of mites collected from mosqui-
toes captured while landing on human sub-
jects was significantly greater than from mos-
quitoes in New Jersey light traps at the same
location (Table 2). Prevalence was 2.5% from
the light trap and 14.6% from landings. The
Fisher exact F xalue = 0.0001728.

186

Great Basin Naturalist

[Volume 58

Table 2. Mite prevalence on female Ae. dorsalis captured in New Jersey liijht traps versus mite prevalence on female
Ac. dorsalis captured during landings. Landings were conducted the day following the trap night.

New

Jersey tr

ap

LandiTigs

Ae.

Ac.

Trial

dorsalis

Hosts

Mites

dorsalis

Hosts

Mites

1

215

2

2

36

4

7

2

10

0

0

30

6

16

3

7

1

1

3

1

3

4

9

3

8

13

1

1

Total

241

6

11

82

12

27

Discussion

Results of this study indicate that larval
water mites, including T. sphagnoriim, may
prefer Ae. dorsalis as a host and that the mite
population may be dependent upon a large
host population of Ae. dorsalis. Because Ae.
dorsalis is the most abundant mosf^uito species
in Natrona County and this species is multi-
voltine, the likelihood of mites attaching to
emerging members of this species is high.
Females of this species would also be expected
to return to aquatic oviposition sites in a single
season, whereas both Cx. tarsalis and Cs. inor-
nata overwinter as females (Harmston and
Lawson 1967), returning the subse(juent sea-
son to aquatic sites for oviposition. Conse-
quently, larval mites selecting Ae. dorsalis as a
host would have greater success returning to
an aquatic environment. All 3 mosquito species
have been collected from the same aquatic
habitat, although seasonal diflerences in species
abimdance occur (unpublished data).

Mite prevalence on Aedes in 1993 was the
lowest of the 6-yr study. However, in 1993
Aedes spp. were only 41% of the total coimted
mosquito population compared to an average
of approximately 60% for all years combined.
AdditionalK', most mites were collected from
hosts in August and September 199.3 when (-'.s.
inornata and Cx. tarsalis comprised greater
percentages ol the m()S(|uito population. A re-
duced population of the preferred host and a
later a|)pearaiK(' ol larval nn'tes ma\ ha\t' re-
duced successful attachment.

Moscjuito numbers were highest in 1994,
likely due to the large niuuber oi' Aedes (78%
of all mos(juitoes trajiped). The greatest num-
ber of mites was also collected that year. Inter-
estingK, during 1994 no water mites were col-
lected from citlicr Cx. tarsalis or Cs. inornata,
perhaps dnc to the greater abundance of Ar.

dorsalis available to serve as hosts. In 1994
precipitation was low (National Weather Ser-
vice data), which led to increased irrigation
activity (Alcova Irrigation District personal
communication). Aedes dorsalis is often asso-
ciated with inigated crops and pastures (Denke
and Spackman 1990).

Mite prevalence and abundance figures re-
ported in this study ma>' be low if mite speci-
mens were dislodged from hosts while in the
collecting jars. It is suspected this occurred,
especially on nights when mosc^uito collection
numbers were high.

Mullen (1977) also reported the pre\alence
ol parasitism by Thyasides sphapionnu in the
northeastern United States to be \'er\ low
(<1.0%) on the 4 species oi Aedes and 1 species
of Cidiseta parasitized b\' 7' sphagnoriini in
New York.

Mosquitoes that were collected as they
landed on humans, presumably to feed, had a
higher prevalence of mites than those col-
lected from light traps at the same location.
There are 2 possible explanations for this. One
is that the flight of parasitized mos(}uitoes is
hindered by attachetl mites, and conse(iuentl\
these m()S(iuit()es are more easily captured.
Alternativel); parasitized mosquitoes are li'ed-
ing more frequently to compensate for nutri-
tional loss due to mites. Anopheles crucidiis,
w hen parasitized b\ the water mite .Xrreiiuru.s
pseiidotenuicolis, was found to fi'ed more Ire-
(juentK' than non-parasitizi'd mosciuitoes (l^an-
ciani and iioyt 1977).

if the initial hypothesis is correct, parasitizi'd
mos(|iu'toes ma\ suller increased mortalit\ due
eithei- to a slowci- response b\ the mosciuilo to
its host di'fense mechanism or to predation. 11
the latter is true, the nuisance eai)al)iiit\ of an
indi\ idual parasitized moscjuito may be greater
than that ol a non-parasitized mostpiito.

1998]

Mite P\ii\siiis\i oi Mosoi itoks

187

Last, if parasiti/.cd fcMiuik' inosciiiitocs iwvd
more hlood meals to coinpt'iisatc tor nutri-
tional loss to mites, the\- may be \isiting more
hosts, making them more effeetixe disease
\ I'ctors. Ac'dc's dorsalis is eonsidered a veetor
ol California eneephalitis (Clrane et al. 1977,
Moore et al. 1993). It ma\ he that parasitized
mosquitoes hite more frequently but also have
a lower sur\i\orship than non-parasitized
moscjuitoes.

I^ow mite prexalenee and abundanee dem-
onstrated in this stud\ indieate no potential
lor sueeesslulK utili/inij; mites as a eontrol
agent.

Acknowledgments

Bruce P Smith identified larval mites. I am
grateful to Robert S. Seville and Kenneth L.
Iloff for their support and advice. The Mos-
quito C>ontr()l l^rogram of the City of Casper-
\atrona Count) Health Department is funded
In the Cit\ of Casper, Wyoming, and the
Natrona Coimt)' Weed and Pest District.

Literature Cited

Cr.a.\e, G.T., R.E. Elbel, and C.H. Calisher. 1977.

Transovarial transmission of California encephalitis

\inis in the mosquito Aedes dorsalis at Blue Lake,

Ut. Mosquito News 37:479-482.
Denke, FM., and E. Sp.\ckman. 1990. Mosquitoes of

Wyoming. University of Wyoming, Laramie.
Harmston, B.C., AND FA. LwsoN. 1967. Mosquitoes of

Colorado. USDA, Health, Education, and Welfare,

Pul)lic Health Ser\'ice Bulletin.

Lanci \Ni, C.A., AND A.D. BoYT. 1977. The effect of a para-
sitic water mite, Arrenunis pseudotemiicolis (Acari:
Ihdrachnellae), on the sunival and reproduction of
the niosciuito Anopheles crucians (Dii)fcra; Culici-
dae). Journal of Medical Entomology 14:101.5.

Margolis, L., et al. 1982. The use of ecological terms in
jiarasitology (report of an ad hoc committee of the
.Anicrican Society of Parasitologists). Journal of Para-
sitolog>' 86:131-13.3.

Moore, C.G., et AI,. 1993. Cuidelines for arixnirus sur-
\cillance programs in the United States. U.S. Depart-
ment of lli'allh and Unman Services, Centers for
Disease C^ontrol, Fort C'ollins, CO.

\ii i.i.iN, G.R. 197.5. Acarine parasites of mosquitoes. I. A
critical review of all known records of mosquitoes
[larasitized by mites. JoiuTial of Medical Entomology
12:27-36.

. 1977. Acarine parasites of moscjuitoes. I\'. TiLxon-

onu', life history and behavior of Tlii/as harhigera
and Thijasidcs sphagnorwn (Ihdrachnellae: Thyasi-
dae). Journal of .Medical Fntomolog\- 13:47.5-485.

N.vnoNAL Weather Service. 1991-1995. Primary local
climatological data. U.S. Department of Commerce,
National Oceanic and Atmospheric Administration.

Smiiii, B.P 1988. Host-parasite interaction and impact of
larval water mites on insects. Animal Hc\ iew ol
Entomology 33:487-507.

Snuth, B.P, and S.B. McIver. 1984. The patterns of mos-
quito emergence (Diptera: Culicidae: Aedes spp.):
their influence on host selection by parasitic mites
(Acari: Arrenuridae: Airenurus spp.). Canadian Jour-
nal of Zoology 62:1106-1113.

TSAI, Y., ET AL. 1969. Parasites of mosquitoes in southwest-
ern Wyoming and northern Utah. Mos(|uito News
29:102-110. '

Received 28 April 1997
Accepted 25 November 1997

Great Basin Naturalist 58(2), © 1998, pp. 188-191

VEGETAL CHANGE ON A NORTHERN UTAH FOOTHILL

RANGE IN THE ABSENCE OF LIVESTOCK GRAZING

BETWEEN 1948 AND 1982

Dennis D. Austin' and Pliilip J. Urness^'^

Abstract. — Ree.xaniination of a seniiarid foothill rangeland, first evaluated in 1948. indicated that secondary' succes-
sion continues to shift toward a perennial grass-forh community formerly dominated 1)\ .xeric shrubs, particularly big
sagebrush (Aiicmi'iia trideutata spp. vaseijana). The direct role of livestock grazing in establishment and maintenance of
shrub-dominant plant communities appears confirmed in the decline of shrubs upon cessation of li\estock grazing in
summer and continued browsing by mule deer in winter. The reduction of shrub forages on mule deer winter ranges is a
major factor in population declines.

Ki'ij words: vegetation change. livestock grazing, succession, mule deer

Evaluation of presettlement vegetation on
foothill ranges in the northeastern Great Basin
indicates relative dominance of herbaceous
grasses and forbs over shrubs (Simpson 1876,
Leopold 1950, 1959, Passey and Hugie 1962,
Christensen and Johnson 1964, Hull and Hull
1974, Vale 1974). Generally, perennial grasses
and forbs dominated plant communities on
more mesic foothills, whereas shrubs such as
Vasey's big sagebrush (Artemisia tridentata
vaseyana [Rybd.] J. B()i\in), saltbush (Atriplex
spp. L.j, and greasewood {S(irc()b(itu.s vennicii-
latiis [Hook] Torr.) were more abundant on xeric
and/or saline valley-floor sites at mid-19th cen-
tury (Stewart 1941,' Vale 1975, Umess 1976).

Rapid proliferation of livestock — cattle,
horses, and sheep — after about 1860 altered
this dynamic equilibrium by reducing palatable
herbaceous forages and decreasing fire fre-
quency, allowing increases in less palatable
and fire-susceptible shrubs. Changes in plant
connnunities were rapid. Shrub dominance
became common on Utah foothills by the early
2()th centmy on lands not prcemi^tcd for agri-
culture (Julander 1962). (voncnrrent with the
increase of shrubs on winter ranges, after hunt-
ing regulations ended excessive exploitation
about 1910, mule deer [Odocoileus hciiiioiiiis
Rafincs(|uc) populations gradually expanded
(Leopold 1959, Hancock 19S1).

Unless site potentials are unalterabK de-
graded, retrogression ol'iilanl coniininiily com-

position can be halted and reversed; that is,
elimination of the processes that initiated
change can facilitate secondan- succession pro-
ceeding back toward a condition similar to
what previously existed (Ellison 1954, 1960,
Robertson 1971, Rogers 1982). However, plant
communities will not necessarily duplicate
presettlement vegetation in Great Basin sage-
brush-grass types due to introduction of
adapted annual and biennial weeds such as
cheatgrass [Bromus tectonim L.), Dyer's woad
{Isatis tinctoria L.), and a mxriad of others
(Young et al. 1976, Blaisdell et al. 1982. Young
and Sparks 1985:234, Burger et al. 1986).

An example of remarkabK' rapid secondarx
succession on a northern Utah foothill range
was reported by Smith (1949). Land between
(Jreen and Logan canyons. Cache Count), was
purchased by the Utah Came and Fish Depart-
ment (now Division ol Wildliie f-lesourccs.
DWR) in 1937 as critical deer winter rangi'.
Sunnner use by cattle was innnediately termi-
nated on the DWR property but not on adja-
cent pri\ate land. Smith measiued \egela-
tional differences that had occurred betwi-cMi
1937 and UJIS on tlu' 2 parci'ls. 'fliis paper
reports on a reexamination ol the same areas
in teiins ol axailable xcgi'tation in 19S2 after
an additional .'> 1 yv of deer-ouK use on the
DW'K property (deer range) and alter li\i'-
stoek use had ceased lor about 25 \r on tlu'
pii\ate (hxcstoek range) area.

'RaiigL-land Hesoiirccs l)c|v,rliii.iil, I'lali State Univ.islls. Luuan. I 'T 84322-5230.
^Dece-'ased.

1 88

1998]

Mni: ni:i;H-Li\i;sT()(:k Oka/.inc Hki.vi ionsiiii's

189

SiLDY Aki;a

The foothills Ix'twecMi Green and Logan
ean\()ns lie on the uppermost heneh terraee of
I'leistocene Lake Bonne\ille at about L525 ni
elevation (T12N HIE Salt Lake Meridian, S\V
1/4 sec. 24 and NW 1/4 sec. 25). Deer concen-
trate on this area as traditional winter ran*i;e
and, since curtailment ol li\ t'stock urazing, con-
stitute the major impact on \egetation. Smith
(1949) reported the composition of plant com-
munities under hea\\ sununer lixestock graz-
ing was dominated 1)\' big sagebrush, but con-
tained elements of perennial grasses and foibs
putatively prominent in the presettlement con-
dition QIull and Hull 1974). Important grasses
included Saudberg s bluegrass [Poa .sccunda)
and bluebunch wheatgrass {Elijmus spicatus);
perennial iorhs were arrowleaf balsam root
(Balsaniorhiza sa^iitaia), nudesears {Wyethia
(n)ij>h'xi('(iulis], and one-head sunflower (Heli(i)i-
thclhi iDiiJlora).

According to Ericksou and Mortensen
fl974), soils are limestone-dcnxed Lithic Xeror-
thents on steeper slopes o\er 209^ (Richmond
series, upland ver\' gravelly loams) and Typic
Calcixerolls on slopes of 10-20% (Sterling
series, gravelly loams). Aspect is west-facing.
Summers are hot and dry; winters, cold and
moist. Precipitation averages 468 mm annualK
(29-yr record), over 2/3 of which occurs be-
tween October and April. The excessively well-
drained character of these gravelly or cobbly
soils combined with high exaporation reduces
efTecti\eness of precipitation during the grow-
ing season, thus resulting in dry range sites of
linn'ted pn)ducti\it\'.

Methods

Because plots were not permanently marked
in the original stud> (Smith 1949), exact relo-
cations were impossible. Howe\er, rematch of
photos allowed us to closely approximate tran-
sect sites (personal communication and onsite
tour with A.D. Smith, Kangeland Resources
Department, Utah State Uni\ersit>-, June 1982).
The same sampling procedures for densit\' were
followed in 1948 and 1982 to assure compara-
ble data sets:

In June, 1948, vegetation data were secured from a
series of 100 square foot plots on each side of the
fence, which as far as h\ estock are concerned, sep-
arates the area into two zones. One series of plots

uas tlistnliiitcd aloiiu a transect rouglily at right
angles to the di\ ision teiice. Another pair of tran-
sects was extended jiarailel to the fence crossing
the first transect at right angles. One of these was
within the deer range and the other in the cattle
range. Seventy plots were delimited in each area.
Vegetation data were recorded as number of indi-
\ idiials of each species (Smith 1949).

Because the original 1 9 IS data were not
a\ailable, statistical comparisons between \cars
wt-re not possible. Data between treatments in
1982 were anaKzed b\ standard / test of the
means.

Results .wd Discussion

Density changes among years, major plant
species, and treatments are summarized in
Table 1. This is not a complete listing, but rather
a focus on important species reported in the
1948 analysis (Smith 1949). The main observa-
tions in 1948 on the livestock-excluded deer
range were the increase of some perennial
grasses and forbs and the simultaneous decline
of shrubs, especialK' big sagebrush, after only
11 \r. The 1982 data demonstrated that earlier
trends had continued on the deer range for
arrowleaf balsamroot, bluebunch wheatgrass,
and Saudberg s bluegrass. Of critical impor-
tance, big sagebrush was absent. Indeed, no
exidence of dead big sagebrush plants remained
on the deer range, and, without the earlier
docimientation, one could easiK' conclude big
sagebrush had ne\er been axailable. Moreover,
in 1982 the livestock range, grazed by cattle
from 1948 to 1957, appeared similar to the
deer range in 1948, especially with respect to
dead and li\e big sagebrush. It is predictable
that with additional years of non-use by live-
stock in summer, the livestock range will pro-
gress toward \egetation composition and struc-
ture now present in the deer range.

These vegetational changes occurred in cer-
tain absence of fire, herbicidal application, re-
seeding, or other range management treat-
ments. Thus, it appears that li\estock grazing
of grasses and forbs during the summer grow-
ing season shifted the competition advantage
to shrubs and was the primar> factor driving
succession toward wood\ plant dominance.
Numerous studies support our findings that
spring-summer livestock grazing maintains or
improves shrub stands on big game winter
ranges (Mueggler 1950, Smith and Doell 1968,
Jensen et al. 1972, Harniss and WVight 1982,

190

Great Basin Naturalist

[\'oluine 58

Table 1. Number of plants found in a series of seventy 100-ft- plots on adjacent ranges grazed by deer in winter (deer
range) and by li\ estock in summer and deer in winter (livestock range). The livestock range ceased to be grazed by live-
stock in 1957, and both were remeasnred in 1982.

FOHBS

Achillea milhjolliuin L.'
A^oseris iilaucd (Pursli) Raf.
Balaamorhiza .sagittata

(Pursh)Nutt.
HcUanthclhi uniflora (Niitt.)

tm;.

Hclifintu.s annwi L.
Wycthici amplcxicuulis
(Nutt.) Nutt.

Grasses

Elijmus spicatus (Pursh)

Gould
Koeleria inacrantha

(Lecleh.) Schultes
Poa pratensis L."
Poa secunda Presl."

Browse

Artemisia tridcntafa (dead)

Nutt.
Artemisia tridentata (live)

Nutt.
Chnjsathamnus nauseosus

(Pallas) Britt.
Gutierrczia sarofhrae (Pursh)

Rritt. 6c Rushv

1948

1982

Deer range

Livestock range

Deer range

Livestock ranire

Number of Number of Number of Number of

plots upon plots upon plots upon plots upon

Total which plants Total which plants Total which plants Total which plants

plants occurred plants occurred plants occurred plants occurred

88

676

243
0

64

24

1610

185

88

29

15
16

31
0

—

36

0

0

96

17

3

3

69

3

14

9

8

3

3

68

1
667

1

2

64

64

92

38

38

580

64

2

8

16

8

185

.3.3

—

11

0

0

696

70

140

26

0

0

136

3

2040

0l>
01'
0

28

3

2
68

0
0
0
1

-

29

11

6

04

53

75

11

0

0

398

62

12

6

—

11

1750

69

122

56

98

39

0

0

12S

.-)-

Occurred as small patches only.

"Numliers of plants between deer and livestock range in 1982 were significantly different (P < 0.0.5).

Reiner and Urness 1982, Stevens 1986, Austin
and Urness 1995). Conversely, removal of live-
stock grazing causes increasing grasses and
forbs and decreasing slirui:)s (Laycock 1967,
Anderson and Holte 1981, Austin et al. 1986).
The net effect on foothill rangeland without
livestock grazing is that single use by mule
deer in winter will gradually impose succes-
sional changes that ad\ t'rscK' affect deer habi-
tat canying capacity. Deer range \ allies on this
study site have greath' decreased from 1937 to
1948 to 1982.

Similar trends observed over main imilc
deer ranges in western United States, where
siimincr grazing by livestock has been elimi-
nated or greatly curtailed, give reason for con-
cern about the future of many deer herds
(Julander and Low 1976, Anderson and Holle
1981, Hancock 1981, Austin et al. 1986, Cle-
ments aiul Young 1997). C>ertainly, mule deer

herds reached peak numbers in the eaiK 1950s
and have since declined throughout the Inter-
mountain West (Julander and Low 1976, Han-
cock 1981). Managed lixestock grazing on foot-
hill ranges (Anderson and Scherzinger 1975,
Austin et al. 1983) is a logical managerial solu-
tion to the decline of winter range habitat and
mule deer numbers.

A(:KN()\\LLi")(:MKNTS

This is a contribution of Utah I^ixision of
Wildlife Kesourct>s Project \\-105-K.

Liii'.HvriHK CiTKi:>

• Vndkuson, J.E., .\N1) K.E. lloi.lK. 1981. \egetation de\t'l-
opment over 25 \ears uithout grazing on sagebrush-
dominaled rangeland in soiilheasteiu Idaho. |iiiuiial
of Range Management 34:25-29.

1998]

Mule Deer-Livkst{)c;k Cha/.inc; Relationships

191

Anderson, EA\'.. and H.J. Scmkkzinckk. 1975. Impnninu
qualit\' of winter torat^c lor I'lk !)>■ cattle graziiit;.
Journal ol Hange .Management 2S; 120-125.

Austin, D.D., .\no RJ. Urness. 1995. Elfects ofhor.se ^nu-
ing in spring on .sur\ival, recriiitinent. and winter
injur) damage of shrubs. Great Basin Naturalist 55:
267-270.

AlSTiN, D.D., RJ. Urnkss, .\nd L.C. Eikrr(j. 1983. Spring
livestock grazing affects crested wheatgrass ri'grow tli
and winter use by mule deer journal ol Kaugt' Man-
agement 36:589-593.

Al STIN, D.D., RJ. Urness, .xnd R.A. Hiccs. 1986. \egetal
change in the absence of livestock grazing, mountain
bnish zone, Utah. Journal of Range Management .39:
514-517.

Bi.\iSDELL, J.R, R.B. .MiKK.w. AND E.D. .McAhtiu H. 1982.
Managing Intermountain rangelands-sagebrush-
grass ranches. Cleneral Technical Report IN'T-134.
USDA Forest Senice, Intermountain Forest and
Range Experiment Station.

BiRGER. G.\:, FH. W.\f;NER, AND L.D. Harris. 1986.
Wildlife prescriptions for agricultural, range and for-
est landscapes. Transactions of the North American
Wildlife Conference 51:573—577.

CuKisTKNSEN, E.M., AND H.B. JOHN.soN. 1964. Presettle-
ment vegetation and vegetational change in three
\alleys in central Utah. Brigham Young Uni\ersit\
Science Bulletin, Biological Series IV, No. 4.

Clements, CD., and J.A. Yoinc;. 1997. A viewpoint:
rangeland health and mule deer habitat. Journal of
Range Management .50:129-138.

Ellison, L. 1954. Subalpine \egetation of the Wasatch
Plateau, Utah. Ecological Monographs 24:89-184.

. 1960. Influence of grazing on plant succession of

rangelands. Botanical Review 26:1-78.

Erickson, A.J., AND V.L. MoRTENSEN. 1974. Soil survey of
Cache Valley area, Utah. USDA, Soil Conservation
Service and Forest Service in cooperation with Utah
Agricultural E,\periment Station.

H.WCOCK, N.V. 1981. Mule deer management in Utah —
past and present. Pages 2-27 in EG. Lindzev', editor.
Mule deer workshop — proceedings. Utah Coopera-
tive Wildlife Research Unit, Utah State University,
Logan.

H.\RNiss, R.O., AND H.A. Wright 1982. Summer grazing
of sagebrush-grass range by sheep. Journal of Range
Management .35:13-17.

IlLi.L, A.C., Jr., AND M.K. Hill. 1974. Presettlement
vegetation of Cache Valley, Utah and Idaho. Journal
of Range Management 27:27-29.

Jensen, C.H., A.D. Smith, and G.W' Scotter. 1972.
Guidelines for grazing sheep on rangelands used bv'
big game in winter. Journal of Range Management
25:346-352.

Jll^NDER, O. 1962. Range management in relation to mule
deer habitat and herd productivity in Utah. Journal
of Range Management 15:278-281.

JULANDER, O., AND J.B. Low. 1976. A historic account and
present status of mule deer in the West. Pages .3-20
in G.W. Workman and J.B. Low, editors. Mule deer
decline in the West — a symposium. Utah State Uni-
versity; Logan.

LWCOCK, W.A. 1967. How heavv' grazing and protection
affect sagebrush-grass ranges. Journal of Range Man-
agement 20:206-213.

Leopold, A.S. 1950. Deer in relation to plant succession.
Journal ol Forestrv' 48:675-678.

. 1959. Big game management. Pages 85-99 in Sur-
vey of fish and game problems in Nevada. Nevada
Legislature Counsel Bureau Bulletin 36. Carson
City, Nevada.

MuEC.GLER, W.F. 1950. EfTects of spring and fall grazing
bv' sheep in vegetation of the Upper Snake River
iMains. Journal of Range .Management 3:308—315.

Passev, H.B., AND V'.K. IllGlE. 1962. Sagebrush on relict
ranges in the Snake River Plains and northern Great
Basin. Journal of Range Management 15:273-278.

Reiner, R.J., and RJ. Urness. 1982. Effect of grazing horses
managed as manipulators of big game winter range.
Journal of Range .Management 35:567-571.

Robertson, J.II. 1971. (Changes on a sagebrush-grass range
in Nevada ungrazed for 30 years. Journal of Range
.Management 24:.397-400.

Rogers, G.F 1982. \ photographic histon- of vegetation
change in the central Great Basin Desert. University
of Utah Press, Salt Lake Citv'.

Simpson, J.II. 1876. Report of exploration across the Great
Basin of the temton' of Utah for a direct wagon-route
from Camp Floyd to Genoa in Carson Valley in 1859.
Vintage .Nevada Series [reprint]. 198.3. University of
.Nevada Press, Reno.

Smith, A.D. 1949. Effects of mule deer and livestock
upon a foothill range in northern Utah. Journal of
Wildlife Management 13:421-123.

Smith, A.D., and D.D. Doell. 1968. Guides for allocating
forage betvveen cattle and big game on big game
winter range. Utah Division of Fish and Game Pub-
lication 68-11.

Stevens, R. 1986. Population dvnamics of two sagebnish
species and nibber rabbitbrush over 22 years of graz-
ing use by three animal classes. Pages 278-285 in
E.D. McArthurand B.L. Welch, compilers. Proceed-
ings of a symposium on biologv' of Arteini.sid and
Chrysothaminus . General Technical Report INT-2()0.
USDA, Forest Service, Intennountain Research Sta-
tion.

Stewart, G. 1941. Historic records bearing on agricultural
and grazing ecologv- in Utah. Ecologv 39:362-375.

Urness, RJ. 1976. Mule deer habitat changes resulting
from livestock practices. Pages 21—35 in G.W. Work-
man and J.B. Low, editors. Mule deer decline in the
West — a sv mposium. Utah State University, Logan.

Vale, T.R. 1974. Sagebrush conversion projects: an ele-
ment of contemporarv' environmental change in the
western United States. Biological Conserxation 6:
274-284.

. 1975. Presettlement vegetation in the sagebrush-
grass area of the Intermountain West. Journal of
Range Management 28:.32— 36.

Young, J.A., and B.A. Sparks. 1985. Cattle in the cold
desert. Utah State University' Press, Logan.

Young, J.A., R.A. Evans, and RT. Tueller. 1976. Great
Basin plant communities — pristine and grazed. Pages
18f>-215 in R. Elston, editor, Holocene environment
change in the CIreat Basin. .Nevada .Krcheological
Survey, Research Paper 6.

Received 25 November 1996
Accepted 19 September 1997

Great Basin Naturalist 58(2), © 1998, pp. 192-197

ARDEN R. GAUFIN. 1911-1997:
OBITUARY AND LIST OF PUBLICATIONS

R.W. Baumann' and (J.Z. Jacohi-

Ardcn H. Gdtijiii

Arclcn R. CTUulin was horn in Salt Lake Cit);
Utah, on 25 Decemher 191 L and passed away
on 8 January 1997. He married Ruth Lund in
Septeniher 1936 and to them were horn two
children: Richard and Marilyn. Raised on a
farm in Kaysville, Utah, Arden graduated fi-om
Davis Ilijz;!) School. He attended the Univer-
sity of Utah, receiving hoth his B.S. and M.S.
degrees in hiolog); and then went to Iowa State
University, where he received his Ph.D. in
1950. His doctoral dissertation was a stud\ ol
the protluction ol the bottom laima ol the Proxo
River, Utah. He served as a cajilain in the US.
Army in the South Pacilic during World War
II and received the Bron/e Star.

Arden s lirst position after graduating was
with the Public Health Ser\ice l"jn iromncnial

Health Center in Cincinnati, Ohio. There he
met Clarence Tarzwell and together the\ cham-
pioned the idea that a(]uatic insects are actu-
alK twenty-four-hour instream sentinels of
stream conditions. Their research on Lytle
Creek, Ohio, was very significant in the for-
mulation of the design, methodolog\', and im-
plementation of research on and recognition
of the importance of sampling aquatic en\i-
ronments. Such studies stressed the impor-
tance of complementing physical and chemi-
cal data with biological information. Results of
this applied research helped strengthen the
need to protect a(|uatic life, the true indicators
of environmental health. This in turn led to the
establishment of water quality criteria for pro-
tecting the integiity of aquatic ecos\stems at
the time when states were formulating stream
standards for inter- and intrastate waters.

As a result of his research on integrating
the physical, chemical, and biological compo-
nents of aquatic s\ stems, Arden was selected
to serve on the Public Health Senice National
Advisory Council, which established water
pollution control standards in the 1960s. It
was during this time that Arden became one
of the early members of the Midwest l^entho-
logical Society. He was an a\id supporter of
and participator in this organization that is
now the \ery successful Xoith Ameiican Bcn-
ihological S()ciet\.

Arden was a Professor of liiolog) from f953
to f975 at the l'ni\'ersit\- of Utah, where he
taught a wide \ariet\ of classes. He spent the
sununers from U)(i.3 thiough 1975 at the Lni-
xcrsit) ol Montana liiologieal Station on l'1at-
hcad Lake as \isiting Prolessor ol /oologx aiul
Assistant Diifcloi'. in addition, he worked
dniing the 19()S-69 sehool \i'ar at the Lni\tM-
sily ol Montana eampus in Missoula as i^roles-
sor ol '/oologN and Dirt'ctor ol I''n\ ironniental

'DepurlniiMil of /doIdkv ami Monk- L. lU-aii Lilf Sficiirr MiiNciim. BriKliaiii VdiiiiK University, Hrovii L T h.K)<)2.
^DcparliiuMil uriCnviniiiiiiciilal Scieiiw, New Mexico IliKlilaiuls L'liiversily. I«is Ve^as. New Me.\ico 87701.

192

1997]

AlvDIA H. (JaI'FIN Olilll ahv

193

Biology. The suiniiUMS in Montana and the
ncail))' states and (Canadian proxinees were
some of the highhglits of Ardens hfe. The bio-
logieal station experienees reminded liim of
the summer that lie spent as a graduate student
at the Uni\(,Msit\ of Miehigan, Douglas I^ake
l^iologieal Station.

Over the years Arden guided many graduate
students in a wide variet>' of projeets dealing
\\ ith acpiatie eeosystems. His interests ranged
lioui high mountain lakes to salt ponds near
the (;rc>at Salt Lake. In faet, man)' eolleagues
would sa\ that Arden s greatest contribution to
a((uatie biolog\ is the large number of students
he inllueneed. He was alwa\s reach' to listen to
iioxel ideas and would willingK seek funding to
support a new graduate student, flis help ex-
tended not only to those included as coauthors
in the following list of publications but also to
lunuerous others who studied various aspects
of a(juatic biology. Aj'den helped many students
begin successful careers in biology. For this
we owe him a lasting debt of gratitude.

In addition, he worked with several col-
leagues on projects across the United States:
CM. Tarzwell, stream pollution in Ohio; R.
Patrick, macroinvertebrates and algae of the
Potomac Ri\er; G.W. Prescott, algae in and
around Flathead Lake, Montana; J.F Hanson,
S.G. Jewett, Jr., and W.E. Kicker, stoneflies
(Plecoptera).

Several of Ardens former graduate stu-
dents aided in the preparation of this publica-
tion. Their help and encouragement are much
appreciated: Claron Bjork, Price, Utah; Allen
Knight, Green Valley, Arizona; Alan Nebeker,
Conallis, Oregon; Jack Stanford, Poison, Mon-
tana; Gerald Smith, Ann Arbor, Michigan; Bill
Stark, Glinton, Mississippi.

Following is a list of scientific publications
authored b\' Arden or coauthored 1)\ him with
colleagues and students. Even though every
attempt was made to maintain consistency,
some problems still exist because original pub-
lications were not axailable.

1939. Rees, D.M., and A.R. Gaufin. The termite proh-
lem in Utah. Univer.sit>- of Utah Bulletin 30:8.

1949. Gaufin, A.R. A comparative study of the hottom
fauna productivit\- of the north and soutli forks
of the Prox'o River at Stewart's Ranch, Utah.
Transactions of the Midwest Wildlife Confer-
ence.

19.50. Wilson, J.N., CM. Tiirzweli, and A.R. Gaufin.
L\tle Creek investigations. Environmental
I Icallh Center Activity Report 6:30-43.

1952. (iaulin, A.R., and CM. Tarzwell. Aquatic inver-
tehrates as indicators of stream pollution. Puh-
lic Health Reports 67:57-64.

1953. Gaufin, A.R., and CM. Tarzwell. Discussion of
Ruth Patrick s paper, "Aquatic organisms as an
aid in solving waste disposal prohlems." Sewage
and Industrial Wastes 25:214-217.

19.53. Ingram, W.M., D.G. Ballinger, and A.R. Gaufin.
Relationship of Si)li(i('riin)i solidiiliim Prime to
organic pollution. Ohio Journal of Science .53:
230-23.5.

19.53. Katz, M., and A.R. Gaufin. The effects of sew-
age pollution on the fish population of a mid-
western stream. Transactions of the American
Fisheries Society 82:156-165.

19.53. Tarzwell, CM., and A.R. Gaufin. Some impor-
tant hiological effects of pollution often disre-
garded in stream surveys. Purdue University
Engineering Bulletin, Proceedings of the 8th
Industrial Waste Conference. 38 pp.

19.54. Gaufin, A.R. Mosquito production in polluted
water Pages 21-22 in Proceedings of the 7th
Annual Meeting, Utah Mosquito Ahatement
Association.

1955a. Gaufin, A.R. Save our wetlands. Utah Fish and
Game Bulletin 11:1-3.

19.55h. Gaufin, A.R. Taste and odor in water Utah
Engineering E.xperiment Station Bulletin 72:
99-109.

1955c. Gaufin, A.R. The effects of pollution on our
fishery. Proceedings of the Utah Academy of
Sciences, Arts, and Letters 32:71-74.

195.5d. Gaufin, A.R. The stoneflies of Utah. Proceed-
ings of the Utah Academy of Sciences, Arts,
and Letters 32:117-120.

1955e. Gaufin, A.R. Aquatic prohlems in the desert.
Pages 28-30 in Symposium on ecology of dis-
ease transmission in native animals. Dugway
Proving Grounds, Dugway, Utah.

19.55. Gaufin, A.R., and CM. Tarzwell. Environmen-
tal changes in a polluted stream during winter
American Midland Naturalist 54:78-88.

19.56a. Ciaufin, A.R. An annotated list of the stoneflies
of Ohio (Plecoptera). Ohio Journal of Science
56: 321-324.

19561). Gaufin, A.R. Fishes. Page 51 in Ecological check
lists: the Great Salt Lake Desert series. Eco-
logical Research at the University' of Utah, Salt
Lake City.

1956c. Gaufin, A.R. Wildlife production vs. mosquito
ahatement. Pages 3-4 in Proceedings of the

194

Gkeat Basin Natl r^vlist

[Volume 5'

1956.

1956.

1956.

1956.

1957.

1958a
19581)

9th .Annual Meeting, Utah Moscjuito .Abate-
ment A.s.sociation.

Gaufin, A.R., E.K. Harris, and H.J. Walter. A sta-
tistical evaluation of stream bottom sampling
data obtained from three standard samplers.
Eeologx' 37:643-648.

GauHn, A.R., and CM. Tarz\vell. Aquatic nuicro-
in\ertebrate communities as indicators of
organic pollution in Lytle Creek. Sewage and
Industrial Wastes 28:906-924.

Paine, G.H., Jr., and A.R. Gaufin. Aquatic
Diptera as indicators of pollution in a mid-
western stream. Ohio Journal of Science 56:
291-304.

Roscoe, E.J.. and A.R. (iaufin. Crustaceans.
Page 28 in Ecological check lists: the Great
Salt Lake Desert series. Ecological Research
at the Universit>' of Utah, Salt Lake City.

Gaufin, A.R. The use and value of acjuatic
insects as indicators of organic enrichment.
Pages 136-143 in Biological problems in water
pollution. Seminar transcripts compiled b\'
U.S. Department of Health, Education, and
Welfare.

Gaufin, A.R. Algae and algae control. Utah
Engineering Station Bulletin 89:100-108.

Gaufin, A.R. Check list of fishes. In: Prelimi-
naiy report on the biological resources of the
Glen Canyon Reservoir University of Utah
Anthropological Papers 31:174-175.

1958c. Gaufin, A.R. The effects of pollution on a mid-
western stream. Ohio journal of Science 58:
197-208.

1959a. Claufin, A.R. Biological indicators of organic
enrichment in freshwater Page 237 in Biologi-
cal problems in waste pollution. Seminar tran-
script compiled by U.S. Department of I leallh.
Education, and Welfare.

19591). Gaufin, A.R. Production of bottom fauna in the
Pro\() River, Utah. Iowa State College Journal
of Science 33:395-419.

1960a. (kiufin, A.R. Bioassaxs to determine the to.xic-
ity of pesticides to a(|uatic iuNcrtebrates. Trans-
actions of the 15tli Purdue i ndiana Waste ( lon-
ference.

19601). (iauliii, AH. The ellects of insecticides on
a(|uatie life. Pages I()-I8 in Proceedings of the
13lh Annual Meeting, Utah M()S(|uito Abate-
ment .Association.

i960c. (iaufin, A.R. Organisms as indicators of pollu-
tion. Transactions of the 40th .Vnniial Conici-
ence ol the Western As.socialion of Stale (iauic
and ['"ish Connnissions.

1960(1. (iaufin, A.H. Sunnnary of physiological aspects
ol insecticides on water (|ualit\. Proceedings of

the Conference on Plnsiological .Aspects of
Water Qualit\.

1960. Gaufin, A.R., and G. Borg. O.xidation pond study
in the Granger-Hunter Improvement District,
Salt Lake Count), Utah. Universit\ of Utah
Press, Salt Lake Cit>. 197 pi).

1960. Gaufin, A.R., and J. Sessions. 1960. Stoneflies
(Plecoptera) from Green River in the Flaming
Gorge Reservoir basin, Wyoming and Utah.
In: Ecological studies of the flora and fauna of
Flaming Gorge Reservoir basin, Utah and
Wyoming. Universit)' of Utah Anthropological
Papers 48: 133-139. '

1960. Gaufin, A.R., G.R. Smith, and R Dotson.
A(|uatic sun ey of Green Ri\er and tributaries
within the Flaming Gorge Resenoir basin. In:
Ecological studies of the flora and fauna of
Flaming Gorge Reservoir basin, Utah and Wyo-
ming. Universitv of Utah Anthropological
Papers 48:140-162.

1961a. Gaufin, A.R. The controversial role of insecti-
cides. Pages 14—16 in Proceedings of the 14tli
Annual Meeting, Utah Mosquito .Vbatement
Association.

19611). Gaufin, A.R. Stoneflies (Plecoptera) from San
Juan Ri\ er in the Na\ajo Reservoir basin, Col-
orado and New Mexico. Universit\- of Utah
Anthropological Papers 55, Upper Colorado
Series 5: 114-117.

1961. Gaufin, R.F, and A.R. Gaufin. The effect of low
ox\'gen concentrations on stoneflies. Proceed-
ings of the Utah Acadeni\ of Sciences. .\rts.
and Letters 38:57-64.

1961. (Jaufin, .A.R., L. Jensen, and V. Nelson. Bioas-
says determine pesticide toxicity to acjuatic
invertebrates. Water and Sewage W'orks, Sep-
tember 1961. 5 pp.

1961. Jensen, L.D., and .V.K. Cjaulin. .Vcjuatic survey
of San Juan River and tributaries within the
Navajo Reservoir basin, linivcrsitv ol L lah
Anthropological Papers 55, Upper ('olorado
Series 5:88-^90.

1962a. (Gaufin, A.R. Environnu'utal rf(|uirenients ol
Plecoptera. Pages 105-1 10 ;u liiological prob-
lems in wati-r pollution. .3rd seminar. U.S.
Department ol I leallh, Lchieation, and Wil-
lare,

19621). Gaufin. A.K. How lisli brtathe. I tah Fish anil
Game Hullclin 18:10-11.

1962. Gaufin, A.K., and S.G. Jewell. |r New eapnias
lioni Utah (i'leeopfeia). Wasuiann journal ol
Hiologx 20:(i9-7l.

I9().). knight, A.W.. and A.K. G.iulm. I'lic ericit ol
water How. temperature, and o\\gen eonien-
Iralion on tlie Pli'coplera nymph. AciDiicurid
IKicificd Banks. Proceedings ol the L'tah .Acad-
em\ ol Seienees. .Arts, and Letters 40:175-184.

19971

Arden R. Cal fin Ohih akv

195

1964a. Gaiif'in. A.H. Tin- Cliloiopt'iliclac of Nortli
Amerika. In: J. Illit's editor, 3. internationales
Syniposium iiber Plecopteivn. (lewiisscr unci
Ahvvasser 34/35: 37-49.

1964h. Gaufin, .\.R. S\ .stematic list of Plecojitcra of
Internioiiiitain region. Proceedintis of tlie Utah
Academy of Sciences, Arts, and Letters 41:
221-227.

19(i4c. Gaufin, .V.R. A new species of Ccij)ni(i from
Utali (Plecoptera). NWismanu Journal ol liiol-
og>- 22: .307-309.

19(i4d. Gaufin. AW. 'Paste and odor production in
resenoirs by blue-green algae. Journal of the
American Water Works .Association 56:
1.34.5-1.350.

1964e. Gaufin. A.R. Biological indicators of pollution.
Pages 32-36 in Proceedings of the 9th Annual
Conference on Water for Te.xas.

1964. Gaufin, R.E, and A.R. Gaufin. Diurnal mo\e-
ments offish in Fish Lake, Utah. Proceedings
of the Utah Academy of Sciences, Arts, and
Letters 41: 58-60.

1964a. Jensen, L.D., and A.R. Gaufin. Effects of ten
organic insecticides on two species of stonefK*
naiads. Transactions of the American Fisheries
SocietN- 93:27-34.

1964b. Jensen, L.D., and .\.R. Gaufin. Long-term
effects of organic insecticides on two species of
stonefh' naiads. Transactions of the American
Fisheries Societ>- 93:357-.363.

1964. Knight, A.W., and A.R. Gaufin. Relati\e impor-
tance of \an,ing o.xygen concentration, tem-
perature, and water flow on the meclianical
activit)- and siir\i\al of the Plecoptera n\ mpli.
Pteronarcys californica Newport. Proceedings
of the Utah Academy of Sciences, Arts, and
Letters 41:14-28.

1964. Xebeker, A.V., and A.R. Gaufin. Bioassa\s to
determine pesticide to.xicity to the amphipod
crustacean, Ganinuirti.'i Idcu.sfris. Proceedings
of the Utah .\cademy of Sciences, Arts, and
Letters 41: 64-67.

1964. Rabc, FW., and \.R. Gaufin. Some limnologi-
cal effects of fertilizing three circjue lakes in
the Uintah Mountains. Proceedings of the
Utah Acadeni) of Sciences, .Arts, and Letters
41:25.5-260.

1965. Funk, W.IL, and A.R. Gaufin. Ctmtrol of taste-
and odor-producing algae in Deer Creek Reser-
voir. Transactions of the .\merican Microscopi-
cal SocietN 84:263-269.

1965. Gaufin. .\.R. Environmental requirements of
Plecoptera. Pages 10.5-110 in Biological prob-
lems in water pollution. Seminar transactions
compiled b\ U.S. Department of Health, Edu-
cation, and Welfare.

1965. C;aufin, A.R., L.D. Jensen, A.V. Nebeker, T Nel-
son, and R.W. Teel. The to.xicity of ten organic
insecticides to \arious aquatic invertebrates.
Water and Sewage Works, July 1965. 4 pp.

1965. (iaufin, A.R., and D.B. McDonald. Factors in-
fluencing algal productivit) in Deer Creek
Resenoir, Utah. Transactions of the American
.Microscopical Societ\ 84:269-279.

1965. Knight, .\.\\.. and ,\.R. Gaufin. Function of
stonefl) gills under reduced dissoKed o.\>gen
concentration. Proceedings of the Utah Acad-
enn of Sciences, Arts, and Letters 42:186-190.

196.5a. Knight, A.W., A.V. Nebeker, and A.R. Gaufin.
Description of the eggs of common Plecoptera
of western United States. Entomological News
76: 10.5-111.

196.5b. Knight, A.W., A.\. Xebeker, and A.R. Gaufin.
Further descriptions of eggs of Plecoptera of
western United States. Entomolcjgical News
76:23.3-239.

1965a. McDonald, D.B., and A.R. Gaufin. The effects
of pollution upon Great Salt Lake, Utah. Pro-
ceedings of the Utah Academy of Sciences,
Arts, and Letters 42:191-195.

196.5b. .McDonald. D.B.. and A.R. Gaufin. Modifica-
tion of algal control procedures to prevent fish
kills in multiple use impoundments. Proceed-
ings of the Utah .\cademy of Sciences, ,\rts,
and Letters 42: 201-202.

1965. Nebeker, A.V', and A.R. Gaufin. The Capnia
columlnana complex of North America (Capni-
idae: Plecoptera). Transactions of the Ameri-
can Entomological Society' 91:467-487.

1965. Wamick, S.L., and A.R. Gaufin. Determination
of pesticides by electron capture gas chroma-
tography. Journal of the American Waste
Water Association 57:1023-1027.

1966. Gaufin, A.R., A.V. Xebeker, and J. Sessions.
The stoneflies (Plecoptera) of Utah. University
of Utah Biological Series 14:1-89.

1966. Jensen, L.D., and A.R. Gaufin. .Acute and long-
term effects of organic insecticides on two
species of stonefly naiads. Journal of the Water
Pollution Control Federation 38:127.3-1286.

1966a. Knight, A.W, and A.R. Gaufin. Oxygen con-
sumption of sexeral species of stoneflies (Ple-
coptera). Journal of Insect Physiology 12:
347-.355.

1966b. Knight, A.W., and A.R. C;aufin. .Altitudinal dis-
tribution of stoneflies (Plecoptera) in a Rocky
Mountain drainage system. Journal of the
Kansas Entomological Society .39:668-675.

1966a. .Xebeker, A.V, and A.R. Gaufin. New stoneflies
from Idaho (Plecoptera). Entomological News
77: 36-43.

196

Great Basin Naturalist

[Volume 5'

1966b. Nebeker, A.V', and A.R. Gautin. (AiiaiKlromoi-
phism in Rocky Mountain stoneflies (Plecop-
tera: Nemouridae). Entomological News 77:
156-158.

1966c. Nebeker, A.V., and A.R. Caiifin. New Paraleuc-
tra from the Rocky Moiuitains (Plecoptera:
Leuctridae). Entomological News 77:255-259.

1966. Warnick, S.L., R.E Gaufin, and A.R. Gaufin.
Concentrations and effects of pesticides in
acjuatic environments. Journal of the American
Waste Water Association 58:601-608.

1967. Knight, A.W., and A.R. Gaufin. Stream type
selection and associations of stoneflies (Ple-
coptera) in a Colorado River drainage system.
Journal of the Kansas Entomological Society
40:347-352.

1967a. Nebeker, A.V., and A.R. Gaufin. Factors affect-
ing wing length and emergence in the winter
stonefly Capnia nana. Entomological News 78:
85-92.'

1967b. Nebeker, A.V., and A.R. Gaufin. Geographic
and seasonal distribution of the family Capni-
idae of western North America (Plecoptera).
Journal of the Kansas Entomological Society
40:415-421.

1967c. Nebeker, A.V., and A.R. Gaufin. New Capnia
from the Rock-}' Mountains (Plecoptera: Capni-
idae). Transactions of the American Entomo-
logical Society 93:235-247.

1967. Tarzwell, CM., and A.R. Gaufin. Some impor-
tant biological effects of pollution often disre-
garded in stream sun'eys. Pages 21-31 in Biol-
ogy of water pollution: a collection of selected
papers on stream pollution, waste and water
treatment. U.S. Department of the Interior,
Federal Water Pollution Control Administra-
tion (reprint of 1953 paper).

1968. Nebeker, A.V., and A.R. Gaufin. The winter
stonefhes of the Rocky Mountains (Plecoptera:
Capniidae). Transactions of the American Ento-
mological Society 94:1-24.

1969a. Raumann, R.W, and A.R. Gaufin. A new species
of Capnia (Plecoptera: Capniidae) from Ari-
zona. Entomological News 80:75-78.

1969b. Raumann, R.W., and A.R. (;aufin. 'i'hc stone-
flies (Plecoptera) of the Wasatch Moimtaiiis,
Utah. Proceedings of the Utah Academy of
Sciences, Arts, and Letters 46:106-1 13.

1969. Males, D.C;., and A.R. Gaufin. {;omparis()ii of
two types of stream insect drift nets. Linmol-
ogy and Oceanography 1493:459-461.

1970. liaumann, I^W., and A.R. Gaufin. The Capnia
projccta complex of western North America
(Plecoptera: (Capniidae)- Transactions of the
American Entomological Societv 96:435—168.

1970. Gaufin, A.\{. lype-species designation for the
subgenus Utacapnia (Plecoptera: C^apniidae).
Entomological News 81:197.

1971. Raumann, R.W, and A.R. Gaufin. New species
of Nematira from western North America (Ple-
coptera: Nemouridae). Pan-Pacific Entomolo-
gist 47: 270-278.

1971. Gaufin, A.R., and S. Hem. Laboratory studies
on tolerance of aquatic insects to heated water.
Journal of the Kansas Entomological Societv
44: 240-245.

1971. Hales, D.C, and A.R. Gaufin. Obsei^xations on
the emergence of two species of stoneflies.
Entomological News 82:107-109.

1971. Richardson, J.W., and A.R. Gaufin. Food habits
of some western stonefly nymphs. Transactions
of the American Entomological Societv 97:
91-121.

1972. Raumann, R.W, and A.R. Gaufin. The Atnpbine-
mura venusta complex of western North Amer-
ica (Plecoptera: Nemouridae). Natural Historx*
Museum, Los Angeles County, Contributions in
Science 266:1-16.

1972. Gaufin, A.R., WE. Ricker, M. Miner, R Milam,
and R.A. Hays. The stoneflies (Plecoptera) of
Montana. Transactions of the American Ento-
mological Society 98:1-61.

1972. Gaufin, A.R., J. Stanford. R. Clubb, and E. Ni-
songer. Dynamics and productixity of aquatic
invertebrates in a desert enxironment. Progress
Reports Desert Riome, United States-Interna-
tional Biological Program. 19 pp.

1973. Elder, J.A., and A.R. Gaufin. 1973. Notes on
the occurrence and distribution of Pteronarcys
californica Newport (Plecoptera) within streams.
Great Basin Naturalist 33:218-220.

1973a. Ciaufin, A.R. Use of acjuatic invertebrates in
the assessment of water (juality. In: Biological
methods for the assessment of water (jualit).
American Society for Testing and Materials,
Special Technical Publication 528:9(i-116.

19731). (iaufin, A.R. Water quality- requirements of
acjuatic insects. Office of Research and De\el-
()j)nR'nl, U.S. Environmental Protection Agenc\.
I'Aological Research Series 660/3-73-004. S9
PI'-

1973. Stark, B.P, B.R. Oblad, and A.R. Gaufin. An
annolali'd list of the stonefiies (Plecoj)tera) ol
Colorado. Enloiiioioijical News 84:269-277,
301-305.

1974. Bauniami, WW., and A.R. Gaufin. Relocation
of Plecoptera txjie sjii'cimi'ns. Proci'cdings ol
the P"nt()mol()gical Societ>- of Washington
76:450-151.

1974. I'Jder, J. A., and A.R. Gaufin. The toxicity of
three mercurials to Ptcronarcy.s calijornica

199'

Arden R. Gaufin Obituary

19'

Newport, aiul sonic [lossihli' iilnsioloiiical
eflects which iiilhieiKt' fht- toxicities. Miniroii-
mental Researeh 7:169-175.

1974. Gaufin, A.R.. R. Chihl). and R. Ni-well. Studies
on the tolerance of acjuatie inseets to low o.\\-
gen eoncentrations. (ireat Basin Naturalist
34:4.5-.59.

1974. Gaufin, A.R.. and W.E. Ricker 1974. .\dditions
and eorreetions to a list of Montana stoneflies.
iMitomologieal News 85:285-2<SS.

1974. Stanford, J.A., and A.R. Gaufin. 197 I. 1 1\ porlieie
coninuinities of two Montana rivers. Seience
1S5: 700-702.

1974a. Stark. B.P, and A.R. Gaufin, The speeies of
Caliiu'tirki and Donmeuria (Pleeoptera: Perli-
dae). C;reat Basin Naturalist 34:83-93.

1974b. Stark, B.P, and A.R. C;aufin. The genus Diplo-
perla (Pleeoptera: Perlodidae). Journal of the
Kansas Entomological Society 47:433-436.

1975. Branham, J.M., A.R. Gaufin, and R.L. Traver.
Growth of Pleeoptera (stonefly) nymphs at
constant, abnormalK high temperatures. Great
Basin Naturalist 35:51-61.

1975. Gather, M.R., and A.R. Ciaufin. Life histor\'
and ecolog\' oi Me^circys signata (Pleeoptera:
Perlodidae), Mill Creek, Wasatch Mountains,
Utah. Great Basin Naturalist 35:39-48.

1975. Gather, M.R., B.P Stark, and A.R. Gaufin.
Records of stoneflies (Pleeoptera) from Ne\ada.
Great Basin Naturalist 35:49-50.

1975a. Clubb, R.VV., A.R. Gaufin and J.L. Lords. Syn-
ergism between dissolved cwygen and cad-
mium to.\icit>' in five species of ac]uatic insects.
Environmental Research 9:28.5-289.

1975b. Clubb. R.W., A.R. Gaufin, and J.L. Lords. Acute
cadmium toxicity' studies upon nine species of
acjuatic insects. Environmental Researeh 9:
332-341.

1975. Clubb. R.W., J.L. Lords, and A.R. Gaufin. Iso-
lation and characterization of a glycoprotein

from tlie stoiielly. PtcroiKircy.s cdlifoniica. which
l)incls cadiiiiuni. Jonniai of Insect f-'hysiology
21:53-60.

1975. Stark, B.P, TA. Wolff, and A.R. Gaufin. New
records of stoneflies (Pleeoptera) from New
Mexico. Great Basin Naturalist 35:97-99.

1976. Adamus, PR., and A.R. (laiifin. A synopsis of
Nearctic taxa found in acjuatic drift, .\merican
Midland Naturalist 95:198-204.

1976. Gather, .M.R., and A.R. Gaufin. Comparative
ecol()g\' of three Zcipada species of Mill Oeek,
Wasatch Mountains, Utah (Pleeoptera: Nemour-
idae). .\merican Midland Naturalist 95:464-471.

1976. Gaufin, A.R., G.W. Prescott, and J.E Tibbs.

Limnological studies of F'lathead Lake Mon-
tana: a status report. U.S. Environmental Pro-
tection .\genc\. Publication 600/3-76-039. 85
pp.

1976a. Stark, B.P, and A.R. Gaufin. The Nearctic gen-
era of Perlidae (Pleeoptera). Miscellaneous
Publications of the Entomological Society of
America 10:1-77.

1976b. Stark, B.P, and A.R. Gaufin. The Nearctic
species of Acroneuria (Pleeoptera: Perlidae).
Journal of the Kansas Entomological Society
49:221-253.

1977. Baumann, R.W., A.R. Gaufin, and R.E Sur-
dick. 1977. The stoneflies (Pleeoptera) of the
Rock-> Mountains. Memoirs of the American
Entomological Society 31:1-208.

1978. Surdick, R.E, and A.R. Gaufin. Environmental
recjuirements and pollution tolerance of Ple-
eoptera. U.S. Enx'ironmental Protection .Agency,
Publication 600/4-78-062. 417 pp.

1979. Stark, B.P, and A.R. Gaufin. The stoneflies
(Pleeoptera) of Florida. Transactions of the
American Entomological Society' 104:391-433.

Great Basin Naturalist 5S(2), © 199S, p. 198

BOOK REVIEW

Wild Plants and Native Peoples of the Four
Corners. \\ illiaiii \\. Dunniire and Gail D.
Tierney. Museum of New Mexico Press,
Santa Fe, NM 87504. 1997. $22.50, soft-
cover.

This is a handsomely produced, well-edited
volume that provides authoritative commen-
taiy on both native peoples and the indigenous
plants used liy those peoples in the Four Cor-
ners area of the American Southwest. The in-
foniiative and interesting narrative is supported
and enriched by 117 photographs (90 in color
and 27 in black and white). The qualit}' of photo
reproduction is outstanding. Separate chapters
introduce the reader to 4 native peoples still in-
habiting the area: the Hopi, Navajo, Ute Moun-
tain Ute, and Jicarilla Apache. Although brief,
these chapters provide the reader with care-
fulK' selected, reliable information concerning
the histoiy, geographic distribution, culture, and
ethnobotan)' of each ethnic group. Photographs
suppoit the written discussions of each native
culture.

Fifty of the plants most frequently used 1)>'
native peoples are treated individually and in
considerable detail. Each species, illustrated
by well-e.xecuted line drawings and/or color
photos, is discussed in terms of cultural uses
and occunence at 5 national parks (Aztec Ruins,
Canyon de Chelly, Chaco Canyon, Hovenweep,
and Mesa V'erde) where one can see the physi-
cal remnants ol and accjuire detailed informa-
tion concerning the peoples discussed in this
book. Specific uses of each species are enumer-
ated, and techniques employed in their collec-
tion and preparation are often given. In addi-
tion, the authors provide useful references lor
researchers desiring to pursue a topic in greater
depth. An appended "Annotated List of Useful
Plants" treats over 500 species, listing their uses
in each ol 7 categories (basketry, ceremonial
uses and tools, cordages or matting, cKcs and
paints, loods and materials lor smoking, medi-

cine, and structural timloer or fuel) and 5 cul-
tures (Hopi, Jicarilla Apache, Navajo, southern
Paiute, and Ute). Each use/culture listing is
documented by 1 of 40 original references in-
cluded in cited literature.

Any massive effort such as that attempted in
this pocket-size handbook (300 pages of 5 1/2 x
8 1/2 inches) will, of necessity, leave some ques-
tions unanswered and include some statements
with which other specialists will quibble. I
foimd myself wishing to see clinical evalua-
tions of the numerous curative and salutar)'
effects reported for the 423 species listed as
having been used medicinally. CertainK* not all
those species were effective treatments for the
numerous and disparate maladies they were
used against. Likewise, some statements con-
cerning individual plants should be accepted
with caution. I (juestion the author's assertion
that PJioradcndron mistletoe "does not realK'
harm" host juniper trees. By the same token, I
question whetlier pseudoephedrine is produced
by any native American species of Ephedra. Of
pei'liaps more importance, I thought the authors
dismissed too easiK the potential toxicitx ol
crushed chokecherry pits. Pulverized choke-
cherries (cherries and pits) have caused deaths
among Ute Indians ol northeastern Utah when
added to fresh pemmican.

My few (^nibbles notwithstanding, 1 highly
recommend this book lor the libraries ol all
interested in native peoples ol the Four Corners
area. For professional archaeologists and ethno-
botanists, the book will be essential reading. 1
do not know of another single source that is so
packed with valuable, reliable information eon-
cerning the \\a\s in which nativi' peoples have
used the native lloia to facilitate their smv ival.

Kimball \. I larper

Department ol Bolanv and Kaiige Science

Brighani ^bnng Univcrsitv

Prov (), L'i' 84002

198

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LITERATURE CITED, also under a centered main
heading, lists references alphabeticalK in the fol-
lowing formats:

Mack, CD., and L.D. Flake. 1980. Habitat relation-
ships of waterfowl broods on South Dakota
stock ponds. Journal of Wildlife Management
44:695-700.

Sousa, W.P 1985. Disturbance and patch dynamics
on rockv' intertidal shores. Pages 101-124 in
S.T.A. Pickett and PS. White, editors, The ecolo-
gy of natural disturbance and patch dynamics.
Academic Press, New York.

Coulson, R.N., and J.A. Witter 1984. Forest ento-
mology: ecology and management. John Wiley
and Sons, Inc., New York. 669 pp.

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(ISSN 001 7-361 4)

GREAT BASIN NATURALIST voi ss no 2 aph 1998

CONTENTS

Articles

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, I:

systematics and ecology James E. Sublette, Lawrence E. Stevens,

and Joseph P Shannon 97

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, II:

factors influencing distribution Lawrence E. Stevens,

James E. Sublette, and Joseph E Shannon 147

Spotted knapweed distribution in stock camps and trails of the Selway-Bitterroot

Wilderness W. Andrew Marcus, Gary Milner, and Bruce Maxwell 1 56

Breeding birds at the Idaho National Engineering and Environmental Laboratory,

1985-1991 James R. Belthoff, Leon R. Powers,

and Timothy D. Reynolds 167

Mite parasitism of mosquitoes in central Wyoming Margo Frost Spurrier 184

Vegetal change on a northern Utah foothill range in the absence of livestock

grazing between 1948 and 1982 .... Dennis D. Austin and Philip J. Urness 1 88

Obituary

Arden R. Gaufin, 1911-1997: obituary and list of publications

R.W Baumann and G.Z. Jacobi 192

Book Review

Wild plants and native peoples of the Four Corners William W. Dunuuir and

Gail D. Tiemey Kimball T. Harper 1 98

^B

H E

LIB-^A Y
AUG '^ ^ i--^

UNIVERSITY

GREAT BASIN

NATURALIST

VOLUME 58 NO 3 — JULY 1998

M.L. BEAN LIFE SCIENCE MUSEUM

BRIGHAM YOUNG UNIVERSITY

GREAT BASIN NATURALIST

httpV/www.lib. byu.edu/~nms/
FAX 801-378-3733

Editor

Richard W. Baumann

290MLBM

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Brigham Young University

Provo, UT 84602-0200

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E-mail: richard_baumann@byu.edu

Assistant Editor

Nathan M. Smith

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Brigham Young University

Provo, UT 84602-6879

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E-maih nathan_smith@byu.edu

Associate Editors

James C. Callison, Jr.

Department of Environmental Technology'

Utah Valley State College

Orem, UT 84058

Bruce D. Eshelman

Department of Biological Sciences, University' of

Wisconsin-Whitewater, Whitewater, WI 53190

Jeffrey J. Johansen

Department of Biology, John Carroll University

University Heights, OH 44118

Boris C. Kondratieff

Department of Entomology, Colorado State

University Fort Collins, CO 80523

Paul C. Marsh

Center for Environmental Studies, Arizona

State University, Tempe, AZ 85287

Jerry H. Scrivner
Department of Biologv'
Ricks College
Rexburg, ID 83460-1100

Stanley D Smith
Department of Biology
University' of Nevada-Las Vegas
Las Vegas, NV 89154-4004

Robert C. Whitmore

Division of Forestry, Box 6125, West V'^irginia

University, Morgantown, WV 26506-6125

Editorial Board. Richard A. Heckmann, Cliair Zoology ; Jerran T Flinders, Botany and Range Science;
Duke S. Rogers, Zoology; Bruce A. Roundy, Botany and Range Science; Richard R. Tolman, Zoology: Larry L.
St. Clair, Botany and Range Science; H. Duane Smith, Monte L. Bean Life Science Museum. All are at
Brij^ham Young University. Ex Olhcio Editorial Board niemhers include Steven L. Taylor, College of Biology
and Agriculture; and Richard W Baumann, Editor, Great Basin Naturalist.

The Great Basin Naturalist, founded in 1939, is published quarterly by Brigham Young University.
Unpublished manuscripts that further oui- I)iol()gicaI understanding of the (Ju-at Basin and surrounding areas
in western North America are accepted for publication.

Subscriptions. Annual subscriptions to the Great Basin Naturalist for 1998 are $25 for individual sub-
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issues are in print and available for sale. All matters pertaining to subscriptions, back issues, or other busi-
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Editorial Production Staff

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CopyriKlit © 1998 l)y Brigham YounK University
Ofricial puhlication date: 1 July 1998

ISSN()()17-3(il4
6-98 750 2fi(S29

The Great Basin Naturalist

Published at Provo, Utah, by

M.L. Bean Life Science Museum

Bhic;ham Yf)UN(: Unineksiit

ISSN ()()17-3(il4

\ oeume 58

31 July 1998

No. 3

Great Basin Naturalist 58(3), © 1998, pp. 199-216

GAP ANALYSIS OF THE VEGETATION OF THE
INTERMOUNTAIN SEMI-DESERT ECOREGION

Da\icl M. Stoms^ Frank VV. Davis^, Kenneth L. Driese^,
KelK M. Cassidy^, and Michael P Murray^

Abstkact. — a conserxation gap analysis was conducted for the Interinoiiiitaiii Senii-Desert ecoregion to assess the
representation of land-co\er t\pes within areas managed primarih for biodiversity ohjecti\es. Mapped distributions of
plant communities were summarized by land-management status categories. The total amount of land penuanentK' pro-
tected in the ecoregion is <4%, and most types that are characteristic of the region have <l09c. Of 48 land-cover t\pes,
20 were found to be particularly vulnerable to potential loss or degradation because of low level of representation in bio-
diversity management areas and the impact of expected land-use activities. Cap analysis data and findings will be useful
in providing a regional perspective in project impact assessment and hiture consenation planning within this ecoregion.

Key words: '^ap analysis, land cover, land management, conservation assessnwnt. National Ve<ietati<m Classification
System, alliance.

In recognition ol tho alaiining hut largely
unmeasnred con\er.sion and degradation of
native habitat, nian> consenation hiologists
have recommended protecting representative
samples of all natural ecological connnunities
as a goal for prescrxing biological diversit\
(e.g., Shelford 1926, Connnittee on the Study
of Plant and Animal Connnunities 1950-51,
Austin and Margules 1986, Shafer 1990, Scott
et ah 1993). Underlying this "coarse-filter"
approach is the assumption that protecting
ecosystems or habitats will simultaneously
confer protection on most plant and animal

species (Noss 1987, Franklin 1993. Orians
1993). While this approach sounds straightfor-
ward in principle, a lack of comprehensixe
and consistent data on the extent, location,
and management of ecological comnumities
makes it (juite challenging to implement. Fim-
damental questions have often been beyond
our capacitx' to answer with any confidence;
for example. How well are communitx' types
represented in areas specialK' managed for the
preservation of l)iodi\ersit\ ?

Scott et al. (1993) outlined a "gap analysis"
meth()d()l()g\ to identify the imderrepresented

' Institute for Computational Earth System Science, University- of California. Santa Barbara. C.\ 93106.
-Department of Botan>. Uni\crsit\ ofVVyoniing, Laramie, V\'Y 82071.

^Washington Cooperati\e Fish and Wildlife Research Unit, University of VVa.shington, Box a57980, Seattle. W.V 9819.5.
"•Idaho Cooperative Fish and Wildlife Research Unit, University of Idaho, Moscow, ID 83844.

199

200

Great Basin Natl tulist

[N'olunie 58

plant communities, or gaps, in the representa-
tion oi biol()<j;ical cli\'ersit\' in areas managed
primariK' for long-term maintenance of native
wildlife populations and natural ecosNstems.
This approach uses medium-scale mapping of
land cover and land management as the only
practical solution for assessing the conserva-
tion status of biodiversity across ecological
regions co\ering hundreds of thousands of
scjuare kilometers. Originating as a pilot stud>'
in Idaho (Scott et al. 1993, Caicco et al. 1995),
gap anal\ sis has been expanded into a national
Gap Anal\ sis Program (GAP) coordinated by
the Biological Resources Division of the U.S.
Geological Survey (formerh- the National Bio-
logical Service). Initial published results have
focused on analyses at the state level for Idaho
(Caicco et al. 1995), Utah (Edwards et al. 1995),
and Wyoming (Merrill et al. 1996). Since its
inception, howexer, GAP has aimed to provide
a national consenation assessment based on
ecological rather than political planning regions
(Scott etal. 1993).

The objective of this paper is to report the
results of the nation's first multistate gap
analysis of plant communities of the Intermoun-
tain Semi-Desert (ISD) ecoregion (Fig. 1) as
cvuTentK' delineated in the U.S. Forest Senice's
EGOMAP program (ECOMAP 1993, Bailey
1995). Ownership and management status of
land-cover types within the ISD ecoregion
(and 2 subregions) are summarized, poorh'
represented types are identified, and the high-
est consei'vation priorities are identified. Sec-
ondarily, we discuss some ecological and car-
tographic issues of this approach to regional
conservation assessment. Technical aspects of
regional mapping will be treated in Stoms et
al. (in press). Although gap anahsis as defined
by Scott et al. (1993) typicalb includes \frte-
brate species distributions, here we icport onK
plant conmiunitN types.

'I'liis ecoregion was selected lor the piolo-
type regional gaj) anabsis lor bodi practical
and eoiisci\ atioM reasons. I'Vom a practical
standpoint, the iSI) ecoregion was among llie
first for which the recjuisile land-cover and
land-management mapping wcic conipleled
l)\ indi\idual state-le\c'l i'.W lirojects. Addi-
tionally, the area proxides a suitable testing
ground lor demonstrating whether GAP can
overcome technical challenges associaled willi
regional majiping that lia\c eonecincd some

program rexiewers fZiibe 1994, DellaSala et al.
1996). Veiy little land in the ISD ecoregion has
been designated lor maintenance of biodiver-
sity, while potentialK conflicting land uses such
as grazing and cultivation are extensive.
Enough undeveloped habitat remains, how-
ever, for proactive conserxation action to be
effective. Thus, the ISD ecoregion makes a
representative case studv' that could be applied
to other regions throughout the western U.S.
Planning for conservation and ecosystem man-
agement within this ecoregion is imdenvav b\
The Nature Conservanc\' (Sandv Andelman
personal communication), Oregon Biodiver-
sity Project (Vickerman 1996), and Interior
Golumbia Basin Ecosystem Management Pro-
ject (a joint effort b\ the U.S. Forest Service
and Bureau of Land Management; Quigley et
al. 1996). BLM is considering wilderness pro-
posals in Wyoming (Menill et al. 1996). Propos-
als for new wilderness areas in Idaho (Merrill
et al. 1995) and Wyoming (Merrill et al. 1996)
and for new national parks (Wright et al. 1994,
Wright and Scott 1996) are being discussed. A
regional gap anabsis can add valuable infor-
mation for all of these planning programs.

Intermountain Semi-Desert
Ecoregion

The U.S. Poorest Senice s National Hierarchi-
cal Framework of Ecological Units (ECOMAP
1993) was adopted for this ecoregional gap
anabsis. 'Phis division of regional units is
widely used both by federal agencies and The
Natiue Conservancy (The Nature Conser-
vancy Ecoregional Working Group 1996) as
the basis for resource assessments. The frame-
work subdivides the F.arth s surface into suc-
cessiveb' smaller, more homogeneous land
units. The highest level, called the dotwiiUi. is
associated with broad climatic regimes and
gross [)hvsiographv. Domains are split into (//'(/-
sions based on vegetational aHinities. Proviiicis
aie snbdiv isions ol a div ision corresponding to
continental weather patterns, soil orders, and
potential natuial vegetation. I>)mains, divisions,
and |)i()\ inces are all categorized at the eco-
regional level in the framework. Provinces can
be progiessiv cK subdivided \\i[() siihrc<j,i(>ns.
Idiulscdixs. and ultimatelv Idiul units at the
project ])lanning level. 'I'he ISD c^corcgion
used in this gap analvsis is a province in the
F.COMAPhierarchv.

1998]

Cai' Awi.vsis: Intehmolntain Si \ii-Di;si:ivi E( ()Iu:c;i()N

201

100 200 300 400 500

Kilometers

Vvj,. 1. Shaded ifliet iiiiasie of the Intennouiitain Seiiii-Dt'sert ecoregioii and the 2 siihregions, Cohiiiil)ia Plateau and
Wxoiniiiu Basin.

The ISD ecoregion encompasses approxi-
niateh- 412,000 km- in portions of Washing-
ton, Oregon, Idaho, Nevada, C^ahfornia, Utah,
Wyoming, ('olorado, and Montana (Fig. 1).
Two geographicalK disjunct subregions make
up the larger ecoregion, the Columbia Plateau
in the west and the Wyoming Basin in the
east. The ISD boundar> corresponds closely
to the limits of Kiichler's (1970) sagebrush
steppe potential natural \egetation type. The
ISD ecoregion southern boundary' grades into
the Intermountain Semi-Desert and Desert
Province, which tends to be w arnier, drier, and
with greater topographic relief" than the ISD
ecoregion. The Cascade and Sierra Nevada
ranges bound the ecoregion on the west and
the northern Rock\ Mountains on the north
and east.

The combination of soils and climate gen-
erates a characteristic \'egetation often called
"sagebrush steppe" (Ki'ichler 1970), dominated
hyAiicmisid spp. or At riplcx conjciiifolia (shad-
scale) with short bunchgrasses (e.g., Festuca
spp., Pseudoroegneria spp.). The rainshadow
effect produced b>' the Cascade-SieiTa Nevada
ranges fa\ ors shrub co\ er and limits tree coxer
to higher elevations (mostly conifers and aspen),
narrow riparian corridors, or sparse pinyon or
juniper woodland. In low-lying alkaline areas
formed in Pleistocene lake beds and subject to
periodic flooding, sagebrush is replaced b\
saltbush {Atriplex) and greasewood {Sarcoba-
tus) communities. Shrub species are replaced
b\' perennial grasses where deeper soils occur.
Most relati\el\' le\ el land with adecjuate water
supplies has been con\erted to agriculture

202

Great Basin Nati i{\i.is r

[Volume 58

(West 1988). NonnatiN'e annual grasses, espe-
cialK' elieatgrass {Bromiis tcctoriiin), ha\'e in-
\aded the region since the 187()s, suceesstully
converting native steppe coniniunities to exotic
grassland (West 1988) and dramatically affect-
ing ecological processes of this vegetation type.
Despite the relative!)' homogeneous appear-
ance of sagebrush steppe, the ecoregion is
floristicalK' complex. For instance, there are 8
species or subspecies of Artemisia that domi-
nate various plant communities. Three juniper
and 2 pin\'on species occur in different por-
tions of the ecoregion.

Methods for a Regional
Gap Analysis

The first critical issue in mapping land cover
is selecting a classification system that is eco-
logically defensible and yet feasible for map-
ping at a regional scale with remote sensing
and limited field information. The alliance level
of the proposed National Vegetation Classifi-
cation System (NVCS; Federal Geographic
Data Committee 1996) was selected as the
most appropriate schema. Derived from the
UNESCO s> stem (UNESCO 1973, Driscoll et
al. 1984), this hierarchical scheme begins with
structural and broad ecological properties at
higher levels, adding floristic divisions at lower
levels. Alliances are named b>' their dominant
canopy species within structural classes based
on life-form and canopy closure. Proposed
NVCS standards define closed tree canopy
(i.e., forest) as tree cover of 60-100%, open
tree canop\ or woodland with 25-60% tree
cover, shrubland classes with >25% shrub
cover and <25% tree cover, and herbaceous
classes with <25% shrub or tree cover. An
example of an alliance in the ISD ecoregion
would be the Piiuis pondero.sd alliance within
the rounded-crow lied temperate or subpolar
needle-leaved evergreen open caiiopv tree
loniiation. Hecause the same dominant species
also occ ins w ithiii a closed canopy tree forma-
tion, there are 2 P. pondero.sa alliances distin-
guished by canopy closure. Flor simplicity, we
use the teniis/f>/7'.s7 and woodland in the text
ill place ol liie closed and open caiiopN termi-
nology w licii iclcn iiig to land-coM'r classes.

Land coNcr was origiiialb mapped inde-
pendently for each ol the states in the ISD
ecoregion (Kagaii and (,'aieco 1992, (-'aicco ct
al. 1995, Davis et al. 1995, Driese et al. 1997,

Homer et al. 1997, Cassid\' in press). Although
most state GAP projects used 1990 (±2 yr)
satellite imagery from the Landsat Thematic
Vlapper (TM) sensor, combined with field
inventories and existing maps of vegetation in
compiling their land-cover data, they differed
in methods and products. Maps for Idaho
(Caicco et al. 1995) and Oregon (Kagan and
Caicco 1992) used photointeipretation tech-
niques with older, lower-resolution Multispec-
tral Scanner (MSS) images and had larger min-
imum mapping units than the other states. In
contrast, land-cover mapping in Nevada and
Utah was done with digital image processing
of TM image mosaics (Homer et al. 1997). This
approach generally achieved greater spatial
resolution at some expense in classification
detail. The other state projects fall somewhere
in between these methods, using manual pho-
tointerpretation of higher resolution TM data
(e.g., Davis et al. 1995, Driese et al. 1997, Cas-
sidy in press). Few maps \\d\e been xalidated
with a formal accuracy assessment (except see
Caicco et al. 1995, Edwards et al. 1995).

For this ecoregional analysis, a regional
land-cover map was required but with greater
spatial and thematic consistenc\ than was con-
tained in the collection of state-le\el maps.
Therefore an inno\ ative technique was de\el-
oped to utilize the state GAP maps as training
data and then reclassify satellite data into a
connnon set of NV^CS cover types. First, all
land-cover classes in the state GAP maps were
conx'crted to alliances as prescribed In the
NVCS. In some cases it was necessan' to aggre-
gate to a higher \v\v\ where dominant species
could not be distinguished in related alliances
(e.g., deciduous riparian lorest t>pes). Pixels of
multi-temporal satellite imager\ from the
NOAy\ Advanced Nerx High Hesolution Radi-
ometer were then assigned to these coxer
txpes using a maximum likelihood classifier.
Some co\c'r t\pes that were either rare or
occur in small patches wt'rt> not classified with
the 1-kiii- satellite data but were retained from
the original majis. Thus, the final map had a
cDiisislc'ul spatial icsolution (1-kiii- or lOO-ha
pixel si/e) across the entire IS!) ecoregion
while retaining the best Holistic inloriuation
hoiii the oiiginal iiiaps (Stoiiis et al. in press).

Although a eouipreheiisixc' map accuracx
assessment ol tin- regional land-eo\er map has
not hccii mideitaken, the map was compared
to a sit ol landouiK distributed 1-kin- field

1998 J

Gap A\ M.vsis: Kniaioi \i\i\ Si.\ii-I)i.si:ht Ecohkcion

203

plots compiled nationwide by the U.S. I'orest
Service (Zlui el al. I99(-i). Seventy-eiiilit of
these plots occur witliin the ISD ecore.uion.
Iliis small sample size is insudicient lor a sta-
tistical per-class assessment hut adeciuate tor a
prcliminaiN indication ol the strengths and
weaknesses o( the land-co\er map. Each plot
it'cord listed dominant tree and/or shrnh
species and their relatixc canopx coxcr, total
absolute tree coxer in classes similai" to the
NVCS definitions ol open and closed canopy,
presence ol iirasses (identilied as annuals or
perennials), and presence ol auriculture. Based
on species composition and co\ er, each plot was
assigned to one (or in some cases to a set) of die
co\er t\pes in the regional land-co\er map.

Maps of land-stewardship and land-man-
agement status were also compiled for indix id-
ual state gap analysis projects, usually by digi-
tizing lUAI Surface Management Status maps.
Maps ol si)ecial managed areas were compiled
from a wide \ariet\' of sources (see Caicco et al.
1995 and Da\is et al. 1995 for details). These
maps were combined to create a regional map.
(i.\P uses a scale of 1-4 to denote relative
degree of maintenance of biodiversit\ for each
tract ol land. A status ol 1 denotes the highest,
most permanent le\ el of maintenance, and 4
represents the lowest level of biodiversity
management as evidenced by legal and insti-
tutional factors. Each tract of land is assigned
to 1 of the 4 status levels as defined by Scott et
al.(1993):

Status I: An area haxing permanent protec-
tion from conxersion of natural land coxer and
a mandated management plan in operation to
maintain a natural state xxithin xxhich distur-
bance events (of natural type, fre(juency, and
intensity) are allowed to proceed without inter-
ference or are mimicked through management.
Included are Research Natural Areas, many
wilderness areas, national parks and monu-
ments, and Nature Conservancy preserx'es.

Status 2: An area haxing permanent protec-
tion from conxersion of natural land coxer and
a mandated management plan in operation to
maintain a primarilx' natural state, but xxhich
may receive use or management practices that
degrade the (iualit\ of existing natural commu-
nities. Most National Wildlife Refuges, Areas
of Critical Environmental Concern, and some
state parks are included in this categorx'.

Status 3: An area hax ing pemianent protec-
tion from conxersion of natural land cox er for

the majoiit}- of the area, but subject to extractix'c
uses ol either a broad, low-intensity txpc or
localized intense type. It also confers protec-
tion to lederallx listed endangered and threat-
ened species throughout the area. Undesig-
nated public lands managed by the U.S. Forest
Serxice or the BIAI are e.\amples of this status
categoix.

Status 4: Lack of legally enforced easement
()!• mandate to prevent conversion of natural
habitat types to anthropogenic habitat txpes.
Alloxvs for intensixe use throughout the tract.
Also includes those tracts loi- xxhich sufficient
inlormation to establish a higher status is not
axailable. Prixatelx oxxned lands (except for pri-
xatc ccmsenation group resenes), most i^eixirt-
nient ol Defense tracts, and state school lands
are included in this categoiy.

Intersecting the land-stewardship and man-
agement map xxith the distribution of land-
coxier classes results in tables that sunnnarize
the area and percent of total mapped distribu-
tion of each class in different land-stexvardship
and management categories. The percentage
and acreages of cover types in each manage-
ment status category and managed by each
stexvard xvere quantified (Caicco et al. 1995).

Results

Land Cox er and Alliances

Forty-eight land-cox er classes xvere mapped
for the region (Table 1), including 2 cultural
land-use types, 5 nonvegetated or sparselx
x^egetated tyjDes, 16 formations or undifferenti-
ated groups of related alliances, and 25 alli-
ances. Formations tend to be relativelx scarce
txpes that occur in small patches or as linear
features. For instance, the seasonally/tem-
porarily flooded cold-deciduous forest forma-
tion consists ol alliances dominated bx Popitliis
trciniiloidcs, P. jrcmoidii. P. balsainijcra, P.
(ingustifolia, or other riparian tree species. At
the regional scale it xvas not feasible to dis-
criminate betxveen them. Species of pinxon
and juniper hax'e overlapping range (except
Jiinipenis occidentalis, which has a distinct
geographic range), and so were grouped into 3
more general classes. Similarlx; 2 Ccrcocarpus
classes (C. ledifolhis and C. montaiius) that
occur in the ecorcgion could not be distin-
guished in the land-cover mapping. Mixes
of canopy species xvith no clear dominants
xvere also mapped at the formation level. This

204

Great Basin Naturalist

[N'olunie 58

Taiu,E 1. Percentage of mapped area of laiid-c()\er classes 1)\ inaiiaiiemeiit status in the Iiitcnnouutain Semi-Desert
ecoregion. Fonnation names shown in Ixjld italics.

Land-

cover class

Status 1 Status 2 Status 3 Status 4 Total area % of

C^'iri Cvi) (9(1 (9(} (km-) ecoregion

Rounded-crowned temperate or subpolar
needle-leaved ever'^reen closed tree canopy

PifHis coiiloiia lorest

Pinus ponderosa forest

Pinus pondcrusa-Pseudotsuiia incnzicsii forest

Conical-crowned temperate or subpolar
needle-leaved evergreen closed tree canopy

Abies species (A. concohn A. g,randis, or

A. mapufica) forest or woodland
Picea enfichnwinii And/or Abies lasiocarpa

forest or woodland
Pscudotsw^u uwiizicsii forest

Montane or boreal cold-deciduous closed
tree canopy

Fopiiliis trciniiloides forest

Seasonally/temporarily flooded cold-deciduous
closed tree canopy

Popnlus trcinontii. P. Ixdsainifcra. P. anfiustijolia,
P. trcmuhmlcs. Salix, Aluus, Bctiilu, etc.

P.ounded-crowned temperate or subpolar
needle-leaved ever<^reen open tree canopy

Piinon woodland iPiiius rdulis or

P. monophijUa)
Pinyon-juniper woodland iPiuu.s eduli.s or

P. monophi/iid witli /(oii/jcn/.v ostvospcruia

or J. scopuloruin)
Juniper woodland ( [nniixTus o.sfcospcnnu or

J. scopuloruin)
Juniperus occidcntalis woodland
Pinus flcxilis or P. alhicaulis woodland
Pinus conloiid woodland
Pinus jcj)rcyi forest and woodland
Pinus ponderosa woodland

Conical-crowned temperate or subpolar
needle-leaved evergreen ojien tree canopy

Pscudotsufia incnzicsii woodland

Cold- deciduous open tree canopy

Popnlus Irciiiuioidcs woodland
Qucntis i^arrycnid woodland

MicrophylUms evergreen shrubland

Artemisia Iridentata ssp. vaseyana slniihland
Artemisia tridentata-A. arbusvuUi slniihland
Artemisia tridentata slniihland
Artemisia tripartita slniihland
Ptirsliiii Uidculdtil slniihland

14.1

4.1

72.9

8.9

2,726

0.7

().()

.3.6

42.4

54.0

106

<0.1

0.0

0.4

47.4

52.2

1,350

0.3

0.0

5.6

().()

11.1

0.9

2.3

4.4

11.9

0.1

0.0

0.2

51.4

59.6

14.1

52.6

51.1

70.6

46.3

30.4

ri.5

47.3

28.3

183

5.9

0.2

71.3

22.5

606

0.1

1.4

1.2

63.8

.33.5

3,.335

0.8

1.038

1,0.53

332

391

706

0.3

0.3

0.1

0.1

0.2

3.8

57.1

38.9

6,728

1.6

1.1

2.0

51.0

46.0

17.fi09

4.3

7.2

0.5

44.6

47.7

1.141

0.3

3.8

7.2

52.2

26.8

373

0.1

0.0

0.0

68.0

32.0

181

<().l

0.1

3.0

37.9

59.0

7,599

1.9

0.2

1.3

1.9

.50.4

46.3

1,896

0.5

0.0

3.0

13.7

83.3

643

0.2

0.8

2.6

50.5

46.0

24,702

6.0

0.6

4.8

68.7

26.0

46,047

11.2

1.1

2.9

63.7

32.3

117,263

28.6

0.0

1.4

29.4

69.1

3,494

0.9

().()

0.3

29.9

69.8

1,071

0.3

aggrej^atioii occuncd lor coxcr classes such as alliaiiti' is (ktiiii'd l)\ a siihspi'fit's — iiiomilaiii

nioiiiitain hrusli in (lie tcinpcratt' cokl-ck'ciclu- hiti sa.ui'hriish {Artctiiisid tridcntdta .ssp. vaseij-

ous slinil) lonnalioii, iiii.xed salt (k'St-rt shrill) (iiui), where it eould he mapped separately

primaiiK composed oixarioiis A//'//;/c.v species, Iroiii other. \. Iridciildid siihspecies.
and j^rasslaiid l\pes. (brasses were di\ided rhri'c iaiul-usi' or land-coNcr t\ jx-s account

into drN' (e.i!;., Psi'itdoroc^ni'tia and Pott spp.) lor 57'/^ ol the reuion — Artemisia Iridentata

and moist 'e.ii- I'Cstucd spp.) perennial hmich- (29%), agriculture (17%), and .A. Iridtiitdtd-A.

grass, an annual grassland (i)rimaril\ the c.xolic arhiisciila (11%). Other signilkanl t\pc-s include

Broiiiiis tcrtoriDii), and arfilicial seedings ol juui}H'rits occidcntalis (4%), A. tridentata ssp.

A'^r()})\ir())i eristdtnni or I'od iinitensis. One rdsei/dnd ((i^r), mixed salt desert shriil) {(i%).

1998]

Gap Analysis: Lmermolmain Semi-Ulseht Ecukecion

205

Table 1. Contimit'd.

Unci

fOMT (.lass

Status 3 Status 4 Total area ^U){'

'' ( ''"n (km-) ctorc'Kioii

Temperate coUI-decidiunin shruhland

Aiiciimia caiia slinil)laiKl
Mountain hnisli sliruMand
CercoairpiiM U'dijoHus or (' tiumtinnis

shiiililanil
Qtwrcus Udinhclii sliinliland

Scdsoitdlhi tcnipoiiirilii flooded cold-dccidnotis
shruhland

I'.xtremelij xeromorfMc deciduous suhdesert
shruhland with or without succulents

Sarcohatus icnniculatus shriil)Iancl

I'acullalirelti deciduous cxlrcmelfi xeroniorjdiic
siihdesrri shruhland

\li\t'tl salt tlcsert sliriil) i.\/;(/)/(.v si)p.j

Dicarf-shruhland

Artemisia nova dwarl-slinihland

Artemisia arhuscula-A. nora d\\atf-sliiiil)larid

Artemisia ri<iida dwarf-shnililand

Atriplex nardneri dwarf-slniililand

Temperate or suhpalar perennial grassland

l)n urassland-/'s(i«/(>rori:iicn« iA<iropyron)-Poa
Moist iirasslaiid-/r.s7i((Y;

Temperate or suhpolar perennial
grassland-cultivated

Agropijron cristatum st'odiiisis, Poa pratensis.
ha\'fields, and (^onsenation Rescne Proyrain
lands

Temperate or suhpolar annual grasslands or fori)
vegetation

Annual gras.ses-Bro;;i«,v tectorum. etc.

Non-tidal temperate or suhpolar hydromorphic
rooted vegetation marsh ami net land'

Alpine and suhal])iur meadows of the higher
latitudes

Alpine tundra

Wet or dn meadow

Sparsely vegetated land-cover types

Seasonal!) temporarilx flooded sand Hats
SparscK' vegetated sand dimes
SparseK' \egetated boulder, gravel, eohhle,
talus roek

Cultural land use types and surface water
L'rhan or liumaii settlements and mining
Agrieiilture
Open water, ineluding ponds

Regional totals (including cultural land uses and
surface water)

14.3

0.9

59.8

25.0

532

0.1

3.5

1.9

49.3

45.3

3.339

0.8

1.0

1.2

.50.7

47.2

1T36

0.3

().()

0.1

17.6

82.2

379

0.1

2.0

0.8

0.6

0.2

0.2

0.9

10.0

5.2

1.0

0.7

3.4

2.S

43.0

51.9

66.2

68.5

64.9

49.5

45.0

42.1

.32.1

30.5

31.

46.9

2,568

1.996

22,668

8,267

2,415

411,277

0.6

1.5

5.5

0.0

.3.9

66.9

29.3

573

0.1

0.0

8.4

76.5

15.1

1,813

0.4

0.3

0.2

38.2

61.2

881

0.2

0.0

1.0

79.5

19.4

9,898

2.4

0.2

4.3

18.9

76.5

21,222

5.2

0.0

3.1

7.8

89.1

1,927

0.5

2.0

0.7

0.6

50.5

48.2

11,522

2.8

0.2

3S.0

7.2

54.6

518

O.I

0.0

0.0

100.0

0.0

3

<0,1

4.7

4.0

4.3.1

IS.l

177

<0.1

0.0

0.2

73.3

26.5

2,341

0.6

0.9

26.4

47.6

25.2

851

0.2

0.6

1.684

0.4

64,473

1.5.7

2.220

0.5

and auiiuiil urassland (o9c). Se\cntecn txpe.s
had mapped distributions of <1 ()()() km- each
(or 0.25% of the regional areaj.

The land-cover map and Forest Serxice field
plots showed general agreement. Thirt\-one
(409f j of the plots were completeK' consistent
with the land-cover map in both structural
and floristic attributes. Another 17 (229c) plots

were at least partially consistent, such as w here
the same species were recorded but percent
canop\' cover in the plot would assign them to
a different formation type than the map did.
The largest discrepancies tended to l)e betxxeen
grassland and sparse shrub coxer, in part be-
cause it is difficult with satellite data to dis-
criminate accuratelx- the 25% shrub cover

206

Great Basin Natliullst

[N'olume 58

threshold on a continuous gradient from grass
to shrub. Several state maps had a sagebrush-
steppe class that was always assigned to an
Artemisia tridentata alliance at the regional
le\el, even though in some cases the shrub
co\er might be <25%. Another 15 (19%) of the
plots that disagreed with the map were located
within 1 pixels width (1 km) of a landscape
with the correct type according to the plot,
which could be attributed to a combination of
map registration error, mixed pixels at eco-
tones, and more generalK' to the fuzziness of
transitions between alliances. Absolutely wrong
labels, according to the plots, were assigned to
13 (17%) samples. We emphasize that this com-
parison is only indicative of the strengths and
weaknesses of the land-cover map but, due to
the small sample size, conveys no statistical
significance about its accuracy.

Land Stewardship and
Management Status

Sixt)' percent of the land in the ISD ecore-
gion is publicK' owned (Table 2). The steward
with the greatest holdings is the Bureau of
Land Management (45.4% of the total land
area). The U.S. Forest Sei-vice and state gov-
ernments control slightly more than 4% each.
Tribal lands account for 2.8% of the region,
while the U.S. Fish and Wildlife Service,
Department of Energy, Department of De-
fense, Bureau of Reclamation, National Park
Service, and county or regional governments
make up the remainder oi public lands in
descending order of area. Frixate lands, includ-
ing a very small pr()[)()rti()n oi nongoNt-rnnien-
tal organization holdings, constitute nearh' 40%.

Greater than 96% ot the ecoregion is man-
aged such that extractive resource uses are
permitted and biodiversity conserxation is not
a primary' objective (status 3 and 4, Table 2).
()nl\ 0.9% (3648 km-) is designated to be main-
tained in its natural state by formal designa-
tion (status 1), with an additional 2.8% (11,288
km-) managed as status 2 lauds (Fig. 2). The
Bureau of Land Management, U.S. Msh and
Wildlife Service, Deparlinciil oi l^ncrgx, and
state lands constitute the major sti'wards of
this |)r()tected land. I liis icgional pattern ol
small proportions oi status I and 2 wilh
approximately e(|ual amounts of status 3 and I
is repeated in both subregions (Table 3). Tlic
Wxoming liasin has slighlK more niibiic land

but less formalK' protected land than the
Golumbia Plateau subregion.

If the status 1 and 2 managed areas are
examined without regard to steward or site
name but are simply aggregated into disjunct
spatial units, there are 809 separate sites with
a median size of just 252 ha (mean size of 1886
ha). Of these, 228 are <100 ha in size, and
another 399 are between 100 and 500 ha.
Despite the large number of small sites (78%
of the total number), they account for only 7%
of the area of all status 1 and 2 lands. Only 26
sites are > 10,000 ha, but represent >70% of
protected area. Five managed areas are each
> 50,000 ha — Sheldon National Antelope Range
(>220,()0() ha) in northwestern Nevada, Idaho
National En\ ironmental Engineering Lab, Hart
Mountain National Antelope Range in Oregon,
Owyhee River Bighorn Sheep Habitat Area of
Critical Environmental Concern (ACEC) man-
aged by the Bureau of Land Management in
Idaho, and Malheur National Wildlife Rehige-
Steens Mountain ACEC complex in Oregon.

Gap Analysis of
Land-cover Classes

The profile of management status for each
land-cover type for the ISD ecoregion is
shown in Table 1. This table can be sununa-
rized by categorizing the percentage ol total
area of each type within status 1 and 2 man-
aged areas. Categories include types not rep-
resented in any status 1 or 2 managed area,
t\pes with <1%', 1-10%, 10-20%, 20-^50%, and
>50%. The number of land-co\'er t\pes in
each categon' for the region and for each sub-
region is shown in labk' 4. Despite the low-
level of representation across most t\ pes, tlu'
representation is an unbiased sample ol the
communities of the ISD ecoregion (chi scjuare
= 52.57, 43 (If P = 0.849). That is, the pattern
of representation across t\pes is not signili-
cantK different than if sites had btnii si'lecti'd
with the intention of achiexing e(|nal icpre-
sentation for all coxci- t\ pes.

'1"vim;s with no kit'kkskni ation i\ srviis
1 \\l) 2 \l\\\(.ll) AlilvVS. — ()nl\ 2 natural
land-c'oxcr types are coiiipictcK umcpic-
S( iiled within tlu' ISD ecoic-gion ai'cording to
the regional maps: rinus icffrcyi and alpine
tmidia. SimilaiK, scMial toxci l\pi'S are not
represented in status I and 2 lands w ithin I ol
the 2 subregions, e\i'n (hough tlic\ are ri'pre-
scntcd within the ecoregion as a whole. These

1998]

Gap Analysis: Imkkmolmain Si;\ii-Desekt Ecokecion

207

Table 2. Percentage of land by management status by steward in tlie Intermountain Semi-Desert ecoregion.

Status 1

Status 2

Status 3

Status 4

Area

Area

.Steward

'■'(}

'■'"( )

(^(}

(70

(km-)

<-/r)

Private, including NCJOs

0.1

0.5

0.1

99.4

163.005

39.6

(!()unt\ /regional goM-rnnicMt

0.0

().()

100.0

0.0

2

-0.0

State gov ernment

0.1

7.4

19.4

73.1

19.381

4.7

Bineau oll^md Managcnii-iil

0.5

1.7

97.8

().()

186,663

45.4

National Park Sen ice

73.5

26.5

0.0

().()

317

0.1

IS. FisI) and Wildlile Senice

29.8

68.8

1.4

0.0

4,581

1,1

I'.S. Forest Ser\ ice

5.2

0.2

94.6

0.0

16,857

4.1

Tribal lands

0.0

().()

0.0

100.0

11,488

2.8

ni'partment of Eiu-rgv

0.0

69.9

0.0

30.1

3,441

0.8

Bureau of Keclaniation

7.7

2.0

0.0

90.3

1,160

0.3

\lilitan resenations / C^orps of

luiginei'rs

0.0

0.2

().()

99.8

2.161

0.5

Large water bodies

—

—

—

—

2.220

0.5

IS!) ecoregion total

0.9

2.8

49.5

46.9

411.277

100.0

Tabi.K 3. Percentage of land l)v niauageuieut status by subregion in the luteriuountain Senii-Desert ecoregion (does
not include water liodies).

Subregion

Status 1

Status 2

Status 3

Status 4

Area

(km-)

Wyoming Basin
Columbia Plateau

0.6
1.0

1.3
3.5

55.3
47.0

42.8
48.5

118,942
290,617

ISD ecoregion total

0.9

2.S

49.5

46.9

409.559

Tabik 4. Tlie number of laud-cover classes at various percentage levels of representation in existing managed areas
(.status le\el 1 and 2 combined). Does not include open water, Agropyron cristatiiin seedings, or cultinal land-cover
types.

Subregion

# not
represen

ted

# with
<l'7f

#
1-

with
-10%

#
10-

widi
-20%

#
20-

with
-50%

# with
>50%

Total #

Wyoming Basin
Colimibia Plateau

4
4

7

14
20

2
5

4
5

0
1

31
42

ISD ecoregion total

■->

-

26

5

4

0

44

unrepresented hpes in the C()Iinnl)ia Plateau
inelude the V'muH pondcroHa fore.st and T. con-
forta woodland alliances. In the Wyoming
Basin inirepresented t\pes are pinyon-juniper
woodland, nioinitain brush, Cercocarpus ledi-
foliii.s or C. montanus, and Purshki tridentata.

Types with <1% in st\tus 1 and 2. —
Seven alliances or cover types have minimal
representation (<1% of their mapped extent)
within the ISD ecoregion. These include Piniis
ponderosa-Pseudotsiiga menziesii forest, pinyon
woodland, Pitrshia tridentata. Qiicrcus gambe-
///, Artonisia rigida, Atriplex gardneri, and
seasonalh /temporarily flooded sand flats (alkali
pla\a). MinimalK- represented t\pes in one of

the subregions, in addition to those listed for
the ISD ecoregion, are Pseudotsuga incnzicsii
woodland and A. nova in the Columbia Plateau
and Pinii.s flexili.s or P. alhicaiiUs woodland and
diy perennial grassland in the Wyoming Basin
subregion.

Types with 1-10% in st.\tls 1 and 2. —
Twent\-si.x types are in this category, includ-
ing the most widespread ones such as the vari-
ous Jiinipenis and At'tcmisia tridentata t\^es,
Sarcohatits vcnniculatiis and mi.xed salt desert
shnib. dr\- grassland, and annual grassland. The
Artemisia tridentata-A. arbuseula shrubland
type has proportions by status level that are
nearK identical to the region as a w'hole (Fig. 3).

208

Great Basin Natur-^list

[\'olume 58

0 100 200 300 400 500

Kilometers

Fiji. 2. Lancl-iuanat^cMiK'nt status of the Intennountain Sciiii-Descrt ccorctiion (Icxels arc cK'lincd in tlic text).

Types with 10-20% in status 1 and 2. —
Five alliances or cover types have this level of
representation in the ecoregion. These types
are the Pinus contorta forest alliance, season-
ally/temporarily flooded cold-deciduous (i.e.,
riparian) forest, pinyon-juniper woodland, Arte-
misia cana shrublaiid, and seasonalK /temporar-
ily flooded cold-deciduous sliruhlaud.

Types with 20-50% i.\ stahs I wd 2. —
Four types are in this catc.uory — the Pitius
coiilorta woodland alliance, non-tidal oi sub-
polar hydroniorphic looted vegetation (i.e.,
marsh and wetland), wet oi dry alpine or siih-
aipiuc meadows, and s|)arscl\ NC'Uetated sand
dunes. In addition to these t\ pes, the season-
ally/temporarily Hooded cold-deciduous forest
and siniihlaud t\ pc-s ha\'e this lexcl oi repre-
sentation iu the ('olumhia Plateau suhicuioii.

The P. coitlorld forest alliance is similarly rep-
resenttxl in the Wyoming; Basin.

'fvi'i'.s w iTii >5()% ix stah s I \\i) 2. —
'{'here are no t\ pes iu this catetiorx iu tlu'
ecoregion. Onl\ the Piiiiis flcxilis or /! alhi-
canlis woodland t\pc has 67% represcnlation
in till' (loluml)ia Plateau suhreiiion. while the
Wyominii; liasiii has none.

Discussion

I .iiintations of" Reuional
( lap .\nal\ sis

(ia|) auaKsis at the stati' or re<j;ioual scale is
suhject to limilalions peitaiuiuii; to its hasic
assumiitioiis and those rt'lated to technological
liniitalious and ccolouical realities ol mai)i)iu<j;
a spccilic sludx area. We addicss hotli loiuis

1998]

Gap Analysis: Inikkmoi \im\ Si;\ii-Di;si;Kr Ecohkcion

209

Kilometers

Fig. 3. Laiul-iiianagcMiu'iit status ol t\\v Artemisia fridcnluta-A. arhii.sctila sliriihlaiid t\ [ic in the Intcniioiiiitaiii Sci
Desert ecoregioii (levels ari' delliucl in tlie text).

here. Cap anaKsis is definecl as an expanded
coarse-lilter approach to conservation (Scott et
al. 1993). It provides a basehne assessment of
the distribution and management of biodixer-
sit\- elements at a given point in time. As such,
it attempts to characterize the variabihty of
l)iodi\ersit\ across large geographic regions
with moderately low-resolution map informa-
tion. This rapid assessment requires the use of
satellite remote sensing data, supplemented
with a modest amount of field observation and
any existing land-co\ er maps. Some plant com-
munities trequentK' occur in patches below
the 100-ha minimum mapping unit of the cur-
rent mapping phase of gap analysis and conse-

(luentK' ma\ be omitted from or underestimated
in the regional anaKsis. Iheir omission high-
lights the need for complementary fine-filter
assessments at more local scales to investigate
a more complete range of biodiversity in a
region. As a baseline assessment, gap analysis
pro\'ides little or no information on current
conditions or past trends in the community.
Where changes in disturbance regime such as
the increase in fire frequency have caused a
conversion from sagebrush to dense annual
grasses, the land-cover map depicts the cur-
rent grassland type, but the loss of the original
cover type is undocumented. Impacts from
grazing or other activities that change the

210

Great Basin Natl iulist

[\ bin me 58

quality of the cover type but uot its classifica-
tion are not portraxcd.

A similar limitation of uap anahsis is its
undcrK in<i assumption that lan(l-manai2;cment
status is deteniiined In tiic intentions expressed
by the steward in fomial designations or agency
mission statements, not the actual or permit-
ted land uses on specific tracts which tend to
be more difficult to ascertain. For example,
public lands may be inaccessible or othei^wise
not suitable for intensive resources uses and
be de facto wilderness areas. GAP normally
assigns these lands to status 3, however, be-
cause digital map information on site-specific
management is not widely a\'ailable and future
use is uncertain. Most lands under steward-
ship of the Department of Defense are catego-
rized as status 4 (except for such dedicated
sites as Research Natural Areas) because there
is no permanent protection offered for liiodi-
versity. Management may change with the
needs of the national defense or with reassign-
ments of base commanders. Some tracts of
Department of Defense lands, however, are
relati\el\ undistiu-bed compared to some other
public lands. As regional-scale data on land
uses and other threats to biodiversity become
more wideK' axailable in electronic form in the
future, the vulnerability of communities could
be more directly assessed than by using land-
management classes as a surrogate for threats.
\n the meantime, this is the best approximation.

To test the validity of this assumption, we
compared the GAP land-status map with a
map of categories of impact of permitted land
uses on natural ecological processes compiled
for the Interior (Columbia Basin assessment
area (Quigley et al. 1996). For the geographic
area of overlap, there was very close corre-
spondence between the status classifications
based on designation and those based on per-
mitted uses (Table 5). GAP status levels 1 and

2 areas were primariK' managed for maintain-
ing natural ecological processes. Only 3% of
these lands allowed intensive uses. Over 80%
of status 3 lands managed 1)\' the BLM and the
USI'\S were being managed for a \ariet\ ol
ecological and liuinaii needs, most olleii willi
high le\cls ol aeti\it\ and vegetation mani|)ii-
lation. Bouglily \oV( of the aiea in status le\el

3 was also being managed for natural ecologi-
cal processes and conservation ol re|Meseuta-
tive or rare biodiversity elements. Tliiis, 10,000
km-- ol undesignated public land is managed

Taui.K .5. C'onesponcleiicc of G.\P status k'\els based on
desigiiatioii with inanageinent categories from the Inte-
rior (;<)lnnil)ia Basin Eeosxsteni Management Project
(K.'BI'.MP) l)ased on actual and phmned land uses on
national forest and Bureau of Land Management lands.
The ICBEMP categories are summarized as follows; 1 =
natural ecological processes. 2 = non-intensi\e human uses
in eonsenation areas, .3—4 = low-intensit\' human uses in
balance with ecological integrit>; .5—6 = \egetation manip-
ulation for resource use, 7-8 = ecological conditions sig-
nificantly altered by human activities.

c;ap

CBEMP

man

agement

categories

status le\ el

1

2

:3-4

.5-6

7-8

1

S2.S

9.9

4.6

2.8

0.0

2

60.4

20.3

10.9

7.8

0.7

.3

14.2

O.S

4.2

79.2

1.6

in ways compatible with designated G.\P sta-
tus 1 and 2. The premise of GAFJ howexer, is
that without the assurance of formal designa-
tion, the protection offered in current manage-
ment plans cannot be considered long term.
Such areas ciurently managed for low-inten-
sity uses could, however, be designated with
only minor economic impacts. It should be
noted that the Interior Columbia Basin assess-
ment area does not cover the entire ISD
ecoregion, and management category data
were compiled for only BLM and USFS lands.
The findings of this comparison of manage-
ment classifications cannot necessariK' be
extended to pri\ ate or to other public lands.

Despite general consensus among ecolo-
gists and conservation planners that conscna-
tion assessments should be conducted o\er
ecologicalK and biogeographicalK meaningful
regions, there lias been no uni\ersall\ accepted
system for mapping ecoregions suitable for all
pmposes. We chose the FCOMAP mapping ol
regions (Bailex 1995) because it is in wide usi'
througlionl the Foiest Scr\ ice for ecos\stem
management and forms the basis for regional
planning by other groups (The Nature Conscr-
vanc\' Ecoregional Working Group 1990). It is
not clear how dillereul our biological assess-
nicnl might lia\e been il a dilieient rcgional-
i/alion liad been selected. In general. eo\er
l\pes in llie 2 snbregions had similar manage-
ment status, suggesting that ri'latixeK minor
l)oundar\ adjustments would probabK lia\e
little effect on the identification ol conserva-
tion gaps. Where at\ pieal plant conununities
are present onl\ near the boundary ol the re-
gion, we lia\e not highlighted them as high

1998]

Gap Analysis: I\i kkmoi main Si;\ii-DEsi:ivr Ecoi^ecion

211

consc'iA'atioii piiorih'. NO matter \\ hat ccorcsiion
sclic'ine OIK' chooses, the clistrihution of sonic
coniinunitics will span more than a siii>j;le
reiiion. There nia\ he l)iolo<j;icall\ important
\arialion within such connmniities that is
rcilected 1)\ ecoreiiional houndaries. If one s
Uoal is to capture the full ran<j;e of biological
\ ariation of a t\ pe within special management
areas, it ma\ he prndent to assess its status
across its entire range. One such approach is
to assess representation I)\ latitudinal, longitu-
dinal, and elexational \arial)les which have
been found to \ar\ with hiotic composition
and ecological processes (Mike Scott personal
communication).

The land-co\er map of the LSD ecoregion
contains se\eral limitations in classification
that affect the findings of this anaKsis to an
unknown degree. Aside from those related to
the omission of fine-grain patches of commu-
nities, the greatest source of uncertaintx relates
to canop) closure in assigning vegetation to
foiinations. Somx-e maps were not consistent
in how (or whether) forest and woodland were
discriminated. ConsequentK, identification of
tree-dominated formations in the W'CS hier-
arcln is probabK' less reliable than dominant
canop\ species information. Tree-dominated
co\er t\ pes, howe\ er, are minor components
of the xc'getation of the ecoregion and occur
primariK at the margins. The accmacy of the
separation of grassland from shrubland along
the continuous gradient of increasing shrub
densit)' is also uncertain in the land-cover map.
The greatest uncertaintx' between alliances
occurs among various sagebrush species and
subspecies, which were not always distin-
guished in the source maps. To some extent
these were identified in the regional land-
cover map w ith ele\ation data. The final point
to emphasize is that some coxer types could
not be meaningfulK- assigned to an alliance,
such as where the \egetation has no clear
dominant species. As an example, mountain
brush is an aggregate class representing a mix-
ture of deciduous shrub species. No species
dominates this t\ pe and the mix of dominant
species \ aries betv\een locations, so no alliance
named for a dominant species was practical. In
other cases the difficult) lies with the NVCS
schema. Where indi\ idual alliances are all rare
and closeK' related (e.g., seasonally/temporar-
il\ flooded cold-deciduous forest), it was nec-

essary to aggregate to the formation iexcl.
Thus, the (luantitatixe findings should be con-
sidered as preliminary indications of potential
gaps in the coarse-filter repres(Mitation of
plant conununities.

Management Implications
of the (lap Anal\ sis

\\ ith these limitations in mind, we draw on
other published literature to interpret the raw
numbers provided by the analysis. On the
basis of level of representation in status 1 and
2 areas, the degree to which land-co\er t)'pes
are characteristic of the ISD ecoregion, and
the extent of historic loss or degradation of
hal)itat or modification of disturbance regime,
we have tentatively categorized land-co\er
types by relative priority for conser\ation
attention. Higher-prioritx categories are listed
in Table 6. States in which more than 2(Wc of
the mapped distril)ution occurs, and stewards
who manage at least this amount, are also
shown in Table 6 to alert principal stakeholders
of planning and management responsibilities.

Highest priority t\pes have minimal biodi-
versity protection and are vulnerable to
expected land-use activities; their extent and
management status ma\' he crudeK' estimated
at the scale of regional mapping. Seasonally/
temporarily flooded cold-deciduous forest and
shrubland t\pes generalK' occur in narrow lin-
ear strips adjacent to ri\ers and streams, w hile
marshes and meadows tend to be quite small.
These patterns make them difficult to map
comprehensively. Further, they contain many
different alliances consisting of a \'ariet\ of
dominant species, and so the status of indi\id-
iial liparian alliances is unknown. Riparian
t\pes depend on flood scouring for germina-
tion, which has hequentK been pre\ented by
dams (Noss et al. 1995). Thus, simply allocat-
ing nature reserves without other manage-
ment actions aimed at maintaining ecological
processes will not preserve them. Further,
these 4 types are sensitive to disturbance and
\aluable for wildlife habitat. Native perennial
bunchgrasses are poorK' represented in status
1 or 2 lands (both t\"pes at <5%) and ha\ e been
substantially modified b\ introduced annual
grasses or con\erted to agriculture. Three-
fourths of Kiichler s fescue/wheatgrass {Festuca/
Pseudoroegneria spp.) potential natural vege-
tation t\'pe in eastern Washington has been

212

Great Basin Naturalist

[\blunie 58

Table 6. States where the most vuhierahle land-cover chisses primarily occur {>209c of the distribution of the type in
status 3 and 4) and stewards most responsible for their manaj^enient {>2()% in status 3 and 4). States and stewards listed
in descending order of extent, if more than one is listed. * indicates rare t\pe that max be underestimated, so other
states and stewards ma\' be involved as mapping is refined.

Land-cover class

States

Stewards

FiKsr-PHioKin (:i..-\s.se,s

Seasonally/temporarily flooded cold-deciduous forest

SeasonalK/tcmporariK' flooded cold-deciduous shnililaud

Dry iixdsshmd-Pfcudoroe'incria (A^wpijron )-P(xi

Moist grassland-F(E'.v?!«Y;

Non-tidal temperate or subpolar In droniorphic rooted vegetation

(marsh and wetland)
Wet or diy meadow
Sparsely vegetated sand dunes

SECOND-PKIOHI'n' CLASSES

Artemisia tridcntaUi ssp. vascijana shrubland
Artemisia Iridciitata-A. arhuscida shrubland
Artemisia trideiitata shrubland
Aiiemisia tripartita shrubland
Piirshia trident at a shrubland
Artemisia caita shnibland
Sarcobatiis vermicidatus shnibland
Mi.xed salt desert shnib {Atriplex spp.)
Artemisia nova dwarf-shrubland
Artemisia arhiiscula~A. nova shrubland
Artemisia rigida dwarf-shrubland
Atriplex gardneri dwarf-shrubland
Seasonally/temporarily flooded sand flats

TlllRD-PRIOKm' CLASSES

Juniper woodland (Juniperus osteospenna or/ sc(>i)idoriim)

woodland
Juniperus occidentalis woodland
Populus tremuloides forest
Populus tremuloides woodland
Mountain brush

Cereocarpus ledifolius or C maiitanus shrubland
Sparsely vegetated boulder, gravel, cobble, talus rock

\VT *

Pvt*

\\T, ID *

BLM, Pvt *

WA, WT. OR

Pvt

OH, WA

Pvt

ID, OR, WA *

Pvt*

\\T. UT *

FS, Pvt *

\\T *

BLM. P\ t *

ID \\% NV

BLM. Pvt

ID, NV, OR

BLM, Pvt

WY, OR

BLM, Pvt

WA

Pvt, BLM

OR

Pvt, BLM

OR

BL.M, Pvt

WY,OR

BLM, Pvt

WY, NV

BLM. Pvt

WY,OR

BLM. Pvt

ID

BLM

OR*

Pvt. BL.M *

WY

BLM

NV

BLM. P\t

WT, ID

BLM. Pvt

OR

BLM. Pvt

OR, \\% NV

BLM. FS. P\ t

\\T, CO

Pvt. FS. BLM

ID

Pvt. BLM. FS

WV, OH

BLM. Pvt

WY

BLM, Pvt

converted to other land u.se.s while the wheat- ness study areas in Wyominu could substantialK

grass/bluegrass {Pseudoroegneria/Poa spp.) type increase the proportion of status 1 foi- this t\pc

has lost 31% of its presettlement extent (Merrill et al. 1996).

(Klopatek et al. 1979). Both perennial grass- Second priority includes t\pes when- their

land types are predominantly on privateK current hiodiNcrsit) protection is niiniinal.

owned lands (dr\ = 77%, moist = 89%). it (\pes are characteristic oi the ccoregion, and

will take a combination of preserxation and
active management to maintain adecjuate rep-
resentation ol the hunchgrass t\'pes. SparseK'
vegetated sand dunes may also be underesti-
mated because dunes beneath sparse vegeta-
tion cover are difficult to recognize in satellite
images. .Vlanagemeut must protect dune-form-
ing processes to preserve the dime conunimit)'
and should also recognize that many plants are
endemic to specific dimes. Despite a modci-
ately high level of rt'iiresentation in status 1
and 2 areas, this coxer type needs a fine-filter
investigation to ensure protection of the iiidi-

they are \ulnerable to expected land-use activ-
ities. Klopatek et al. (1979) reported a lo^r loss
of sagebrush stepi^e to other land uses, largely
agriculture. Localb. the impact on sagebrush
steppe has been nuicli more si'vi're, such as a
substantial conversion ol big sagi'biush habitat
in till- Suake Bivi-r plain (Noss et al. 1995). ()nl\
l^/( ol the sagebrush stciipc li.is been uiial-
fectcd b\ livestock grazing, with 30'^ being
lu-avily grazed (West 1996). The major impact
of grazing has bi'cn a decrease in pei'cnnial
bunchgiasses with a corresiionding incri'ase in
w()od\ shinb lovcr. fhc indoduction ol Bro-

vidual plant species it represents. HL\I wildei- imis tcitoruni has increased lire lr('(|ncnc\ in

1998]

Gap Analysis: 1\ii;k\I()i mmx Si \ii-I)i;si:ivi Ecohkcion

213

main locations to tlic cxtnit that annual urasscs
lia\c' totalK supplantftl sauchrusli (Wt-st 19(SS).
Because of the selectiw u;razin<j; pressure on
l)alatahle species, even lightK' grazed areas can-
not he fulK restored to a pristine condition
(West 199(i). Puhlic agencies ha\'e responded
to the ri'ni()\al ol nati\c' herhs thiontih hea\\
Ura/iiiL!; 1)\ seeding large areas w itli introduced
Ap'i)))i/r()ii crisUitiiin (crested wheatgrass).
Restoring these degraded or seeded sagehrush
steppe sites would he exticnicK e.\pensi\e
and possihK hexond our current understand-
ing (West 1996). The Artemisia tripartita and
Piirshia tridcntata alliances are notewortln
hecause the\ hoth ha\e 70% of their mapped
tlistiihutions on private lands. In contrast, 2/3
of the A. nova type occurs on public lands,
rhe actual management status of A. rigida
(stiff sagehrush) dwarf shruhland, with 61% in
status 4, is onl\ an estimate. It was not mapped
in Idaho where it is known to occur on small
patches of specific soils that were below the
resolution of the original Idaho land-cover
map (Caicco et al. 1995).

The xeric coxer t>pes, including mi.xed salt
desert shrub, Atriplex gardneri (which was
mapped only in the Wyoming Basin subregion
but does occur in the Columbia Plateau), Sar-
cobatus vennicidatiis, and seasonally/temporar-
il\ flooded sand flats, are also in the second-
priorit) categor\. These types tend to be
arranged in distinct gradients of moisture and
alkalinitx' in \'alle\' bottoms, with strong com-
petiti\e sorting of species. Stutz (1978) pro-
poses that rapid exolutionarx' dixergence and
Inbridization within the Atri))lex genus may
be occurring in different \alle\ s in Wyoming,
\e\ada, and Utah. If true, this would argue
for protection of man\ replicates in this ecore-
gion and in the Intermountain Semi-Desert
and Desert ecoregion to the south to nurture
this evolutionary' process. Currently, <2% of
the mixed salt desert shrub t\pe is in status 1
or 2 lands. The seasonally/temporarily flooded
sand flats, or alkali playa, t\'pe is even less well
represented at 0.2%. The A. gardneri and S.
venniculatiis alliances have 1% and 6% repre-
sentation, respectix eK; but arc not highly vul-
nerable to grazing impacts because of the
defense mechanisms of their dominant species.
0\ er 80% of the A. gardneri t\pe was mapped
on public lands, primariK under the jurisdic-
tion of the BLM. Formally designating the
BLM wilderness studv areas in the state of

WVoniing, howcNcr, would contribute veiy lit-
tle additional protection lor these 4 desert
t> pes (.Merrill et al. 1996).

rhird-prioritx land-co\er t\pes are those
that ha\i' low lopresentation in existing biodi-
\orsit\ management areas but do not appear
highly xulneiable from the kinds of acti\ ities
that are most probable. Also included are types
which ha\e complex, higliK' \ariable floristic
composition. These types retjuire further study
to assess their consei^xation status in greater
detail, perhaps with finer separation of alliances
within the type. Juniperus occidentalis has
doubled in areal extent, at least in Idaho and
Oregon, where it has replaced sagebrush
steppe communities as a result of fire suppres-
sion (Miller and Rose 1995) and reduced her-
baceous fuel in the understor)' from heavy
li\estock grazing (W'est 1988). Given that juni-
per woodlands are expanding into sagebrush
steppe, management concern lies more with
the fire regime than necessaril\- increasing their
representation in designated managed areas.
Populus tremuloides forest and woodland are
also dependent on periodic disturl^ance. Moun-
tain brush within the ISD ecoregion is at the
northern limits of its range (Caicco et al. 1995).
It is perhaps one of the most complex classes
in the ecoregion with a diverse mix of canopy
shrubs that can \'ar\' dramaticalK' between
sites. This floristic complexity makes moun-
tain brush a difficult class about which to draw-
meaningful conclusions concerning its protec-
tion status with GAP data, so it needs to be
examined in greater detail. The Cercocarpus
alliance tends to occur on steep, rocky out-
crops which are not prone to development. In
fact, as a fire-sensiti\e species, Cereocarpus
has expanded its lange since the beginning of
fire suppression (Kagan and Caicco 1992).
While not of the highest conservation priority,
it should still receive further consideration
(Merrill et al. 1996). The sparseK vegetated
boulder, gravel, cobble, and talus rock is a
very general class for many types of essentially
bare ground. Little can be concluded about its
biodiversity value e.xcept at a more site-spe-
cific scale.

Fourth prioiit) includes types that tend to
be marginal to the ISD ecoregion. These types
ma> be of concern but are better assessed in
neighboring regions or across their entire
range. These types include all conifer forest
and w oodland t)pes (except juniper woodlands),

214

Great Basin Natl r.\ij.st

[\'olume 58

Quercus <i.am/an(i \\'()ocllancl, Q. <^ainJ)cUi slinib-
land, and alpine tundra. The gap anal\ sis pro-
jects in Idalio and Wyoming in combination
provide some of that broader perspective for a
few of the t\pes marginal to the LSD ecore-
gion. Piniis cont())ia forest and woodland t\'pes
are more characteristic of the northern Rock)'
Mountains where they also appear to be well
represented (Caicco et al. 1995, Merrill et al.
1996). P.flexilis occurs mostly in the Wyoming
Basin on sites unsuitable for most human land
uses. Even though it is not well protected by
formal land-management designations, it is
not higliK' \ulnerable and not a high consena-
tion priority in the ecoregion (Merrill et al.
1996). The Picea engelmannii and/or A. lasio-
carpa forest and woodland t\'pe is widespread
throughout the mountains of Idaho and
Wyoming where it is well represented
(approximately 40% in each state) in status 1
and 2 lands (Caicco et al. 1995, Merrill et al.
1996).

Conclusions

A gap analysis was conducted for the Inter-
mountain Semi-Desert ecoregion using data
compiled from 9 states. Despite limitations in
the data, our gap analysis provides the first
systematic assessment across all ownerships of
the management status of plant conmiunities
within a multistate region. Forty-eight land-
cover tx'pes were mapped at the regional level,
many of which are at the alliance le\el of clas-
sification. Twenty types were determined to
be the highest consei^vation priorities, as they
are especially vulnerable to future losses or
degradation in the absence of formal designa-
tion or active intervention for long-teini biodi-
versity management. Over 96% of the terres-
trial environment within the region is poten-
tially a\ailal)le to intensive human uses for
resources, recreation, or urbanization; the pro-
portions are similar for the Cohnnbia Plateau
and Wyoming Basin subregions. We urge thai
findings regarding indivitlual Ncgetation t\ pes
hoiii this assessment be carehilK xalidated 1)\
regional field iii\ cstigalion lo belter deler-
mine their (iiic Icxcl ol rciiresenlalion and
aclual \ iilncrahih'ly lo ihreals helore poliex
decisions are made and iniplemenled.

One of the nioti\ati()ns lor condneting gaj)
analysis for an ecoregion rallicr ihaii lor |)()liti-
cal juiisdiclions is to rellccl iiioic aecurateK

the vulnerabilit\- of communities over their
ranges. Findings from a sample of the commu-
nit\, such as a single state, could be mislead-
ing and generate inefficient consenation action.
GeneralK, land-cover types had similar man-
agement status in the ISD ecoregion anaKsis
as they did in the 3 gap anab'ses published to
date for Idaho (Caicco et'al. 1995), Utah
(Edwards et al. 1995), and WNoming (Merrill
et al. 1996). Types with low representation
within individual states were likewise poorly
represented in the region. Well-represented
t\'pes at the state level were mostb' conifer for-
est types that occur in \'ellowstone National
Park and large wilderness areas of central
Idaho, which are outside the ecoregion. Thus,
even if these tree-dominated t\'pes had low
representation in the ISD ecoregion, we felt
the\' were not a high conservation prioritx*
regionalb'. This correspondence of state and
regional findings in this particular instance is
probabb' not txpieal.

Beyond the initial conservation assessment,
these findings can be applied in at least 2
additional directions. First, the\ can pro\ ide a
regional perspective when the impacts of spe-
cific land-use proposals are investigated. GAP
data can quantify how rare a community t>'pe
is, where else it occurs, and how well it is rep-
resented in biodi\ersit\ management areas.
Second, the data from GAP can pla> a signifi-
cant role in follow-up conservation planning
efforts at a statewide or regional le\el (Crowe
1996, Viekerman 1996). I^br instance, GAP
data such as shown in iMguie 3 can provide
the missing biodi\'ersit\ dimension in discus-
sions about alternatix e wilderness and national
park proposals (Wright et al. 1994, Mc>rrill et
al. 1995, 1996, Wright and Seoll 1996). The
Nature Conserxancx has alreadx used ihe
GAP database from the Columbia Plateau sub-
region as a coarse-filter to idenlib eandidaU'
areas to ensure adecjuate representation ol all
eonnnunitx t\pes. Because GAP projects are
now nnderwax in almost e\'er\' stati' in the
nation, data to support other regional anal\ ses
and eonserxation planning will soon be lorth-
eoniing.

A( KNOW I IDCMIINTS

Su|)porl ioi' this projeit was pro\ ided In ihe
Gap AnaKsis Progiani ol the I'SCJS Biological
liesoui'ees Di\ ision and the IBM Corjioration

1998]

Cap Analysis: I\ii,i{\i()i \iai\ Si;\ii-Di-:,si-:ht Ecohkcion

215

EnxironnuMital Rescarcli Proiirain. \\V arc
especial!) liratefiil to Jinmn Katiaii for help in
conipilin.u; the iet!;i()nal lan(l-c()\( r map. Rex
('rawford, Marion Heed, and Boh .\h)sele\ of
The Natnre ('onser\ane\ reviewed a draft of
tlie land-eoxer map. Michael l^ueno dexcl-
oped software to process state GAP land-co\ er
maps into a more consistent regional product.
Patrick Crist, Blair Csuti, Chris Crue, Collin
Homer, Mike Scott, and 2 anon) nions review-
ers prt)\ided helpfnl ad\ice and connnents.
We also thank Lori Kleifgen and Tom Kohley
for i)r()\ iding data to the project.

LlTi:i{ATl HK ClTKI)

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Received 17 April nj97
Accepted 27 Sei)tcinl)er H-J97

CriMt Basin Xattinilist 58(3), © 199S, pp. 217-230

NATURAL HISTORY OF A SALINE MOUND ECOSYSTEM

Hoht'it Iv Blank' -. Jaincs A. Yomi'j;', jaiiics I). IVciit'. and Dchra Iv I'aliiKHiisf '

AliSTR.\CT. — Along tin- niaiiiins ol [ilavas in norlliwcstcrn Nt'xada, a salt-tolerant plant connnnnity occupies mounds
that dot a largcl\- unvcgetated landstapi'. In this cMnironnii'iit we studied soil de\elopiiient and plant-soil relationships,
rhe mounds, a\eiaging 0.3 m in height, are occupied b\' the shrubs Allenwljcu occkleiitalis (iodine hush), Sarcobatus
lennicttlatits (black greaseuood), and Atriplex lentiformis ssp. torreijl (Torrey salthush). Distichli.s spicata (desert salt-
grass) is the onK' herbaceous plant occupying this community. Soil salinity decreases with depth in this environment,
and content of atjueous-cxtractable solutes is significantly influenced by site-specific vegetation. Content of silt, clay, and
salt in mound surface horizons suggests a chronosetiuence of mound formation, with the youngest at the barren playa
interface and tlie oldest at the upland vegetation border. Plant demography and mound soil stratigraphy suggest that a
pulse of plant recruitment and moimd building occiUTed dim'ng a time of neoglacial cooling. As a substrate for plant
recruitment, mounds ha\e a limited lifespan because deposition of eolian-transported salts and geochemical c\cling b\'
plants (juickK' render them too saline for seed germination. The apparent periodicit\ of mound formation precludes
definitive conclusions regaiding those mound characteristics favorable for plant reciTiitment and survivorship.

Key words: Allenroliea occidentalis, Atriplex lentiformis .s/j/j. toi"re\i, eolkin dust, Sarcobatus \ermiculatus.

Vegetated inouiicls, hummocks, or hillock.s
occur in desert climates worldwide (Shantz
and Piemeisel 1940, Bendali et al. 1990, Danin
1991). The origin of these features is generally
thought to be capture of eolian sediment by
\egetation (Gile 1966, Viisek and Lund 1980),
thus the term pythogenic hillock (Batanouny
and Batanounx' 1968). Plants occupying these
mounds often ha\e adapti\"e growth character-
istics such as aerial structures and roots and
runners fa\'oring the capture and stabilization
of eolian materials (Bendali et al. 1990). Colo-
nization of mounds b\' cr>ptogamic organisms
lends further stability to the soil (Danin 1991).

During the Pleistocene the Lahontan Basin
of northwestern Nevada consisted of numer-
ous intcrcomiected lakes (Russell 1885). At the
onset of the Holocene, these plu\ ial lakes re-
ceded lea\"ing a complex of liighK saline, fine-
te.xtured lacustrine sediments intermixed with
coarser-textiu'cd, less saline, deltaic, beach,
and offshore bar deposits. Fhniatile sands and
eolian-reworked material offered a favorable
substrate for plant colonization culminating in
the presentlv di\erse plant communitv (Young
et al. 1986). '

P()st-plu\ial recruitment on tiie \cr) saline
pla\'a sediments, however, was problematic.
Xeal and Motts (1967) suggested that plant

recruitment on plazas ma\ liinge on the for-
mation of large desiccation cracks. These cracks
accumulate sediment, presumably of low
osmotic potential, capture seeds, ha\e higher
available water content for establishing seed-
lings, and begin the process of mound Ijuild-
ing. Another pathway of plant recruitment on
saline playas occurs when phreatoph\tic
species are able to tap into low osmotic poten-
tial groundwater and then begin mound build-
ing (Neal and Motts 1967). Assumed in the
previous recruitment process is a favorable
establishment phase sufficientK' long to allow
plant roots to reach the water table; this process
likely hinges on optimal climatic conditions
and a high water table. Jacobson and jankow -
ski (1989) present another mechanism for plant
recruitment on Siiline pla> as. At discharge spots,
evaporative concentration establishes dense
brine pools. Crystallization of gypsum in capil-
lar)' zones heaves the grotmd, which can then
be colonized b\ haloplu tic plants.

Research was initiated to understand plant-
soil relationships and the history of mound
development in this arid, saline environment.
Two basic (juestions were asked: (1) Is mound
formation a prerequisite to the establishment
and evolution of plant communities? (2) Con-
xerseK; are mounds happenstance, a natural

'U.S. Department of .Agriculture. .Agricultural Research Seriice. Ecolog\ of Temperate Desert Raiigelands Unit. 920 \'alle\ Road, Reno, W 89512.
-Corresponding author.

217

218

Great Basin Natl haust

[Volume 58

consecjiience of aerodynamic liaflFliiiii; by vege-
tation in an enxironment witli a high tlux of
wind-transported material? Working hypothe-
ses developed during initial fieldwork postu-
lated that the principal pedogenic processes
operating were eolian dust capture by vegeta-
tion to form mounds, and that new mounds
form in upland positions while mounds closest
to the barren playa are eroding.

Methods

The studx was conducted in Eagle Valle\'
(39°44'N, 119°2'W), 64 km east-northeast of
Reno, Nevada. Eagle Valley is a small embay-
ment of pluvial Lake Lahontan bounded to the
northwest b>' the Truckee Range and to the
southeast by the Hot Springs Mountains. The
western boundary of the playa was the termi-
nus of the Truckee River dining phnial peri-
ods and consists of coarse-textured deltaic and
reworked eolian sands. Elevation oi the bar-
ren playa surface in the study area is 1234 m.
At maximum lake levels during pluvial cycles
of the Pleistocene (Morrison 1964), water cov-
ered Eagle Valley to a depth of approximately
100 m. Presently, water ponds on the barren
pla\'a surface onl\' during years of heavy
runoff Our principal study area is at the east-
ern end of the playa (Sec. 26, T22N, R26E).
The location is a gradient from barren, flat,
fine-textured, salt-encrusted sediments to a
higher, coarser-textured, and less saline com-
plex of re\\orked beach material, eolian sands,
and allux ial colluxial material emanating from
Hot Springs Moim tains. This transitional area
where halophytic plant communities exist on
mounds is the focus of this study (Fig. 1).
Nearby Fallon, Nevada (elevation 1209 m), with
average precipitation of 12.5 cm \r"'' had the
following precipitation (cm) during the stu(l\
period: 1988 = 12.9, 1989 = 12.2, 1990 =
14.5, 1991 = 8.3, 1992 = 10.4, 1993 = 14.0.
1994 = 13.3. leased on data hoiii inonitoi"
wells installed throughout the study area, the
water table is <3 m in most years. .Mounds
are dominated by Allcnrolfcd ocridcntalis ([S.
Watson] Kuntze), Atriplcx Icntijorinin ssp. tor-
reiji (fS. Watson] 11. M. Hall 6c Clements), and
Sarcohatiis vcnniciihilns (| I look.] Torrey) and
by the grass Disliclilis spicdhi ([L.j CIreene)
(Young et al. I9S6). In (lie less saline and coarse-
textured beach and colhuial (l('|)()sits, \cgela-

tion is donnnated by Atriplcx confei'tifoJia and
Sarcohatiis hailcyi iBillings 1945).

Six mounds, each supporting A. occidentalis,
S. icnniciilatii.s, A. lentifonnis ssp. torreyi, and
D. spicata, were randoniK selected in 1989.
From each mound we collected soil samples
beneath each indi\ idual plant microsite (approx-
imately 10 cm deep excluding the surface crust).
We also collected composite soil samples from
(1) barren mound surfaces, to 10 cm, (2) the
surface 10 cm of lacustrine material beneath
the mound centers, and (3) interdune sediment
inmiediately adjacent to the moimds, 0-10 cm.
A satmation extract was prepared for each soil
sample (U.S. Salinity Laborator)- Staff 1954).
Electrical conductivity was measured with a
salinity drop tester. Ion chromatography was
used to quantify Na+, K+, Cl", NO3-, and
SO4-2.

To explore the spatial distribution patterns
of soluble salts in mound en\ ironments, we
randomly selected 3 mounds in 1990. A grid
pattern was overlain on the mounds. At nodes
of the grid, we collected a 7.6-cm-diameter
core to the depth at which lacustrine sediments
were encountered or to 30 cm, w hichex er was
shallower; the surface crust was excluded.
Samples were placed in bags, brought to the
laboratory, air-dried, and stored until ana-
lyzed. Extraction of soluble species was facili-
tated b\- placing 10 g of the homogenized orig-
inal sample in 50-mL centrifuge tubes, adding

10 mL deionized water, and shaking for 1 h.
The tubes were centrifuged and subsamples
tested for electrical c()nducti\it\ with a salin-
it\ drop tester and for pH with a glass elec-
trode. Other subsamples were diluti-d with
deionized water to appropriate lexels lor
anaKses b\ tlie ion chromatograph for Cll",
Br-,'N03-,'s04-2, Na+, K+, Mg+^, and Ca+2.
Boron was determined using the azomethine-

11 colorimetric procedure (John et al. 1975).
For one of the mounds, particle size analx sis
was done as described below. The spatial dis-
tribution of each iiuiiN idual attribute is pre-
sented in an .\Y/ contour lill chart laiililated
by a connnercial giai^hics piograni.

In 1990 wc described a S('(|ikik(' oI 7 soils
along a transect encompassing llic w itUh ol the
nioinided area lioui the barren pla>a surlaii'
southeast to the less saline upland inferlaci'
(Iransi'cl distance = 1.2 km). .\ backhoe was
used to e\ia\ate (o a depth ol approximalcK
3 111. Soils were desi ribi'd using established

1998]

IYava Soil

219

I-"ig. 1. Landscape photograph ot study areas showing mounds occupied l)y Allenvoljeu occidcntcdis. I'br 50 inoiiiicl
measured, the a\erage length was 3.1 m {s = 1.8), average width was 1.9 {s — 1.1), and a\crage height was 0.3 ni.

protocols (Soil Sunxn' Staff 1984). Samples of
each liori/on were returned to the laborator)
tor hiither characterization. We (juantified the
lollowinii attributes: (1) organic carbon by the
dichioniatc digestion procedure (Nelson and
Sonmiers 1982); (2) particle-size distribution
after removal of organic matter and soluble
salts (Gee and Bander 1986); (3) saturated
paste extraction (U.S. Salinit) Lal)oraton- Staff
1954) with (juantification of anions and cations
I)\ ion chromatography. Clay-sized fractions
reserved from particle-size analyses were pre-
pared for and examined b\' X-ra>' diffraction
using standard procediu'es f Moore and
lieynolds 1989). The \er> fine sand fraction
was examined with a petrographic microscope
to identify its mineralogy (Brewer 1976). The
silt-sized fraction was isolated by diy-sieving
ot original samples and examined b\ .\-ra\ dif-
fraction.

At approximatcK l-mon intenals in 1991,
we collected soil samples at depths of 20, 40,

and 60 cm from 4 randoniK- selected mounds.
After transport to the laboratory in sealed glass
\ials on ice, the samples were immediately ana-
K'zed for gra\ imetric water content and total
soil water potential (J])ecagon SC-10 thermo-
couple psychrometer). Calibration of the ps\-
chrometer was facilitated using saturated salt
solutions of LiCl (-294.4 MPa), NaCl (-38.0
MPa), KCl (-21.7 MPa), and KNO3 (-7.5
MPa), and NaCl solutions with potentials of
-3.2 MPa and -1.8 MPa.

To quantif}^ eolian dust fluxes and chemical
content, we placed marble dust collectors (3
replicates) on the barren pla\ a surface approx-
imately 8 km southwest of the study area. The
marble dust collectors consisted of approxi-
mately a 5-cm depth of glass marbles placed in
33 X 24-em teflon-coated cake pans placed on
the soil surface. Collectors were sampled bi-
monthly fiom June 1994 through June 1995, at
which time dust weight was recorded. A sub-
sample of the dust was dissoKed in deionized

220

Great Basin Naturalist

[Volume 58

water (1-g sample 25 mL H.7O) and analyzed
for CI- NO3- SO4-2, Na+, and K+ using ion
chromatography and for Boron using the azo-
methine-H colorimetric procedure.

Results
Soils

Except for the soil described on a large
dune (soil 5), soils along the transect have
grossly similar morphology and stratigraphy
even between moimd and intermound micro-
sites (Table 1). Vesicular surface crusts overly-
ing soft, sandy loam layers are common to all
soils. Hues are 2.5Y in surface layers grading
to 5Y in lower layers (Munsell color system). A
textural discontinuity exists in all soils exam-
ined: sandy loam surface layers overlie silty
clay loam varved lacustrine sediments. The
upper several centimeters of the lacustrine
unit contain many indurate nodules ranging
from 1 to 5 cm in diameter. Tubular pores are
abundant in the finer-textured material. These
pores are in places peripherally coated by what
appears to be organic material, perhaps old
root channels. The proportion of sand in sur-
face horizons decreases from the barren playa
surface to the higher portion of the landscape
at soil 7; silt and clay content correspondingly
increases. In excavated sections of mounds,
graded-bedding and cross-bedding were evi-
dent in the sinface coarse-textured material.

Organic carbon levels are very erratic among
soil horizons (Table 1). There is a slight increase
in organic carbon in the lower mottled, re-
duced horizons. Organic carbon is highest in
the surface crust of soil 7. Visual inspection of
this layer did not show any e\ idence of root-
ing activity, but the crust had encased seeds
and fruits of haloph\'tic species that occup\-
the mounds.

Saturation paste extracts show the extreme
salinity of this environment (Table 1). Com-
plete solubilization of some salts may not ha\c
occurred for some samples gi\en the soil-to-
vvater ratios used. 'I'hese s\stems are dominated
by Na+ and Cb. bc-\fls of \a+ and Cl , as
well as other solutes, generally decline with
depth. Ivxtractable SO4-2 values are erratic
among soils and among soil horizons. Soils on
the lowest part of the landscape (1,2, 3, and 4)
have a secondary bulge in profile SC^.,"^ levels,
which is absent in soils 5, (\ and 7. Lc\cls of

K"*" are inconsistent among soils and among
horizons. Levels of NO3- are extraordinarily
high in the surface crust of all soils, generalK
declining rapidly with depth.

Clay-sized mineralogy is similar among the
soils examined. In the coarse-textured material
overlying varxed lacustrine materials, K-satu-
rated treatments produce reflections corre-
sponding to lattice spacings for kaolin, mica,
and a poorly ciystalline, randoniK' interstrati-
fied smectite-illite. With Mg''"- saturation and
glycol intercalation, the randomb interstratified
component expands to 1.6 nm with \en broad
reflections. Lacustrine sediments are dominated
by smectite. One unusual X-ray trace was for
the 5th layer of soil 3, the horizon with anom-
alously low pH (Table 1). The pattern was
completely amorphous save for a very broad
maximum centered at 0.40 nm, which is indica-
tive of opaline silica (Jones and Segnit 1971).

X-ray diffraction was used to examine the
silt-sized mineralogy of soils 1, 3, and 6.
Samples were dry-sieved from original mater-
ial to consene water-soluble minerals. A peak
matching algorithm was used to detect miner-
als in the samples. The principal e\aporite
mineral identified in the silt-fraction was
halite (NaCl), which occurred in all soil la\ers
above the lacustrine sediments. The onK other
evaporite mineral identified was bloedite
(Na2MgS04-4Il20), which occurred in la\er 1
of soil 3. Other principal minerals in all hori-
zons in decreasing order of abundance were
plagioclase feldspar, (}uartz, calcite, and mica.
CA'psum (CaS04'2H20) was a major mineral
component in layers 4 and 5 ol soil 3 and
the surface horizon of soil 5, both \ cgctati'd.
Diagnostic peaks lor sepiolite (ideal =
Si |oMg,s03()(OH)4(()1 12)481120) were found
in the 5th layer of soil 1. No zeolites were
identified in the silt fraction e\en though
saline pla\a enxironnuMits are known to foster
tlieir I on nation ( Ming and Mninpton I9S9).

Mineralog) ol the xc-iy line sand Iraction
was determined b\ optical methods and (luan-
tilied using tlie line count inctliod (Brt'wcr
197(')). Samples wi-re washed with water to
remoN'e solnbh' salts. Tlic niineralog\ ol soil
aboxc laeustrini- sediments is dominated l)\
plagioclase feldspar and ([uartz with minor \<)1-
canic glass, hornblendes, mica, and carbonates.
Much ol the lacnstrine material consisted ol

1998]

V\.\\ \ Son.

221

(liutoni tests partial!) or coinplcteK cciiKMitccl
l)\ ail isotropic inati'iial that appears to ho sihca.

Phmt-Soil Hchitioiishi|")s

The coiitt'iit ol ainu'ous cxtrattahli' sohites
varied sipiitieaiitK ainoiiu colleetioii microsites
(Fitj. 2). The most sahne niierosites were uii-
vegetated areas atop luomuls and the soil he-
neath i^reasewood. Soil collected in the uinej.^-
etated /one adjacent to mounds and the playa
material directK' beneath the mounds had in
Ueneral the lowest le\els ol e.xtractahle solutes
amonti; the collection microsites.

Using a hackhoe, we were able to imco\er
a root SNstem of A. occidcntalis that emanated
liom a moimd and extended oxer 10 m into
the unNctietated interspace. The directionalitx
of the root s\stems sut:;gests linkaj^es among
mounds, although we did not excavate a com-
plete root system from one moimd to another.
The diameter of larger roots was o\er 5 cm.
Most large-diameter roots had o\er 90 growth
rings, the oldest ha\ing 120 rings. Soil-water
relations data collected in 1991, a wetter than
normal \ ear, show the extremeK' negative total
soil \\ ater potentials characteristic of this envi-
ronment (Tal)le 2).

Soil samples from 3 spatialh' separated
mounds were collected in a grid pattern to
determine the spatial distribution of aqueous-
soluble solutes. Canop\" coxerage of the mounds
bx' A. occidcntalis ranged from approximately
1/2 (Fig. 3aj to much less than 1/2 occupied
(Fig. 3c). Spatial distribution of aqueous-solu-
ble solutes differs considerablx' among the 3
mounds. There is a correspondence betxveen
levels of aqueous-soluble solutes and location
of plant canopies for mounds a and b. In mound
a the highest electrical conductixitx and K"*"
occur beneath S. lennicidatm plants; for mound
c, levels of Mg"*"- and S04~- are especially
high beneath A. occidcntalis plants on the
south side of the mound. Mound b, xvhich has
the greatest canopy coxerage bx' A. occidcn-
talis, generally has the lowest solute concen-
tration near the top of the mound correspond-
ing roughlx- to a nonxegetated area. There is
also a directional aspect of solute distribution.
Manx solutes are highest in the southxvest
quadrant (all mounds). Coarse sand content
shoxvs a gradient from north to south (mound
a). Ven- fine sand content is highest at the top
of the mound, and silt and clax are highest at
mound edges (mound a).

Folian Dust

The bimonthlx eolian dust flux on the bar-
ren plaxa surface axerages oxer 130 g m~^
(Table 3). The dust is dominantlx composed of
Na"*" and Cl" (nearlx- 40% bx xxeight) xvith x erx
liigh lex'els of water-soluble S04~^, K"*", and
\()3~. Concentration of plntoto.xic boron
axerages over 1400 mg kg '.

Disci ssioN
.\h)und Pedogenesis

Particle-size distribution indicates that soil
development began on a surface that w^as rela-
tively coarse textured in comparison to the
underlxing lacustrine material. Depositional
fabrics such as cross- and graded-bedding and
the areal extent of the coarse-textmed veneer
suggest it is a renmant offshore bar likely re-
xxorked by beach and xxind action as the pluvial
lake receded. Thus, mounds are a composite
of eolian material oxcrlying offshore beach
deposits.

In the Lake Lahontan basin, given geomor-
phic surface stabilitx, the proportion of fines
(silt and clax) increases xvith time x ia the steady
capture of eolian dust in the soil skeletal hame-
xxork of sand- and gravel-sized particles (Chad-
xxick and Da\ is 1990). In oiu" studx the propor-
tion of fines in moimd surface layers increases
from the barren plaxa interface to the sur-
rounding upland. Based on the Chadxvick and
Davis model, youngest moimds are closest to
the barren plaxa, xxhich is supported bx mound
stratigraphx. Mounds closest to the ban-en plaxa
shoxv greater relief and hax^e more visual exi-
dence of recent eolian sand deposition. More-
oxer, as expected, there is a general increase
in mound salinity from the plaxa to the upland
because, as time increases, cumulative addi-
tions of salt-rich eolian dust (Table 4) and
plant gcochemical ex cling of salts also increase
(Robert 1950, Charlex and West 1977). Expan-
sion of xegetated mounds into barren plaxa
surfaces is opposite the general conclusion that
plaxas in xxestern United States haxe generally
enlarged during the Iloloccne (Black-xvelder
1931, Malek et al. 1990). Hoxvever, Eagle Val-
ley may be unique due to the immense vol-
ume of coarse-textured deltaic sediments gen-
erallx upxvind of the studx area (prevailing
xx'inter storm \\ inds from the northxvest).

The controlling factors of pedogenesis in this
environment are eolian erosion and deposition.

222

Grk.m Basin Naturalist

[Volume 58

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I^LAV\ Soil.

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224

Great Basin Naturalist

[Volume 58

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Fig. 2. A(jiieous extractable solutt's as intluenced In collection Tiiicrosite. Codes are as follows; BAKE = top ol nioiiiul
with no vegetation; PAD = surface soil of unvegetated mound interspace; PBD = lacustrine sediment lieneath mound;
SAVE, ALOC, ATTO, and DISP = collected beneath S. venniculatus, A. occidentalis, A. torretji, and D. spicata, respec-
tively. Values are means ±1 s^.

extreme aridity, high sahnity, halopli) tic vege-
tation, and aeration status of the lower lacus-
trine sediments. Erosion and deposition via
wind action are a constant in these salt desert
environments (Young and Evans 1986). The
magnitude of eolian transport in the study
area is immense (Table 3). Moreover, deposi-
tion of dust in obstructions such as plant cano-
pies would rajiidK increase their salt content
to levels too high lor future seedling recruit-
ment. The situation thus exists where eolian
materials both build the vegetated mounds and
are also partially responsible for iheir deuiise
at some later date due to excessive salt accu-
mulation and eventual plant death. As will be
discussed later, we arc not sure mound build-
ing is contemiioraneous with steacK' salt accu-
nnilation Irom dust, or whether the mound-
building phase recjuires some different climate
from tliat present when less saline, coarser-
textured eolian dust is more plentiful.

rhe study areas scant precipitation pre-
cludes extensive leaching ol solutes ihrough
the soil. Steady additions of salt-rich eolian dust
and plant deposition ol salts on the soil smface
ajipear to (piickly make mounds cxfremeK
saline.

One ol llic coiisc(|ii(iK'cs ol cxtrcincK liigli
salt content in soils is tlic accelerated pli\ si( al
breakdown ol sand-si/cd particles to silt-si/cd

particles by salt weathering (Goudie et al. 1970).
In addition, the high salt content in conjunc-
tion with aridity' and plant processes leads to
extreme alkalinization such as seen in S. ver-
micultitus microsites (Robertson 1983). The
locally high pH condition enhances the weath-
ering of primarx' minerals via increased solu-
bility of alumimun, iron, and silicon (Lough-
nan 1969).

At present, plant lactors come into pla\ onl\
on the mounds themselves. One plant pedo-
genic aspect is the biogeochemical concentra-
tion of elements that accelerates momul salin-
ization due to the captiue of t'olian dust alone.
The yearly fall of leaxcs and seeds becomes
incorporated, enriching the mound siu'lace
hori/on with organic matter, \egetation seems
to pla\ a role in the formation ol g\psum. as
only \cgetated mounds contain nicasurabli'
(inantitics. (Jvpsinn lormation max be a Innc-
tion ol plant concentration of calcium and sul-
lur in mound soil to such lc\t'ls that gypsum
can i)recipitate. Alti'rnati\c'ly, mound iniciocli-
niate max foster the crystalli/.ation ol gxpsiun
\ ia salt exclusion from ice (Marion and Grant
1997).

Another laitoi" in the genesis ol these soils
is the extrenu'K reduced nature ol the lacus-
trine si'diments as indicated b\ gK'\ soil col-
ois, mottling, and the picsenci' ol pxrite (I'cS)

1998]

TvHl i: 2. \\at(

■I relations, by de

ptii, of iiioiind.s (v

Pl,AV\ Soil,
allies are means with

standard errors in

parentheses; n =

225

4).

Date

CraN

iuH'tiic water content
In di'ptli (em)

Tota

1 soil water potent
1)\ ck'jith (eni)

ial

20

40

60

20

40

60

13.2 (6.5)

13.7 (6.0)

9.4(5.1)

5.0(1.4)

4.8 (0.8)

%

20.9 (6.5)
26.5 (13.0)
27.6(10.3)
2.3.9(10.6)
29.5 (6.7)

24.8 (5.4)
27.1 (5.9)
23.1(11.1)

28.7 (7.3)
29.0 (7.0)

\IP.,

5/30/91

mom

7/8AJ1
8/30/91
9/30/91

-22.7 (3.7)
-15.2 (3.4)
-14.6 (4.3)

-22.1(2.7)
-18.8(1.5)

-11.2(3.2)

-12.7(5.1)

-6.8(1.5)

-8.0 (1.8)

-5.1 (0.4)

-8.3 (2.2)
-5.2 (0.8)
-6.3(1.3)
-8.0(2.1)
-4.5 (0..3)

TaBLK 3. .\\erage hinionthK dnst flux from June 1994 through June 1996, and water-soluble composition of dust col-
lected on the banen pla\a surface just west of the stud\' area. Standard en^ors in parentheses.

Dnst flux

Months

1 g m-- 1

Sodium

Sulfate

Nitrate

Potassium

Boron

g kg-

1 dust

1 1 1

jiil-Aug

81 (14.6)

171 (44)

27 (5.8)

704 (245)

2128 (462)

1.302 (2.32)

Sci:)-Oct

17(2.5)

120 (27)

33 (6.0)

884 (304)

1600 (429)

1,547 (401)

\o\-Dec

172 (9.9)

193 (20)

94 (4.7)

565 (240)

2215(140)

1712(181)

j.in-Feb

159(66.1)

150 (46)

45 (15.4)

6 (2.6)

2076 (629)

1592 (92)

\iar-Apr

157 (32.8)

151 (59)

41 (17.3)

293 (159)

1880 (1,59)

1414(68)

Ma\-Jun

2,39 (.53.7)

136 (42)

21 (6..3)

23 (1,58)

1690 (,3,55)

1316 (8,5)

coatings. Reduced conditions are likeK' facili-
tated by a shallow water table, but subdued oxy-
gen diffusion rates through the fine-layered
sediments nia\ pla\- a role. Lack of oxygen for
root respiration will retard root growth of man\-
plants (Marchner 1986). In addition, strongK
1 t'duced conditions will increase the solubilit\'
ot metals such as Fe and Nln (Stinun and Mor-
gan 1996j. The unusualK low pH in the 5th
la\er of vegetated soil ,3 ma\ be a consequence
ot changes in aeration status of the soil. If this
horizon pre\iousl\ contained reduced sulfur
minerals such as pxrite, its subsequent oxida-
tion could lead to the low pH obser\'ed (Nord-
strom 1982).

Natural History' of Mounds

Vasek and Lund (1980) present a model ol
mound evolution on a pla)a that in\()l\cs \eg-
ctation succession. Priman" mound establish-
ment on a playa begins with eolian dust en-
trapment by species oiKochia, which have high
sodium tolerance. As mounds enlarge and
accumulate nutrients, conditions are favorable
for the establishment oi Athplcx lenfifonnis ssp.
torreyi, which promulgates mound expansion
to a critical size at which time thev coalesce.

These complex mounds are favorable for the
recruitment of new species such as Atriplex
confertifoJia. Haplopappus acradeuiau.s, and
Staulcya })inu(it(i. Further biogeochemical en-
richment of the mound in Na"*", Cl~, K"*", Ca"*"-,
and Mg"*"- from litter fall and eolian dust leads
to eventual death of plants and mound ero-
sion. Soil pH and solute content are control-
ling factors in plant distribution in arid envi-
ronments of the western United States (Gates
et al. 1956, Skougard and Brotherson 1979).

There is no evidence to suggest plant suc-
cession occurs on moimds at Eagle Vallev playa.
Mounds begin and end with occupation by A.
occidentalis and/or S. venniculatus, and occa-
sionally by Atriplex confertifolia and Atriplex
lentifonnis ssp. torreyi.

Mound estal)lishment potentialK' could have
begim sometime in the latest Pleistocene as
pluvial Lake Lahontan dried (Mifflin and Wheat
1979, Morrison 1991). The mounds, however,
are far younger because they lack profile dif-
ferentiation indicative of nearly 10,000 yr of
pedogenesis. For example, in a similar playa
margin environment, a clay-rich, differentiated
soil horizon formed in less than 3500 \t (Peter-
son 1980). Moreover, field research in the Lake

226

Great Basin Natlii.\list

[\ blume 58

PLANTS

4-

3.5-

• * -f *

3-

• • •

2.5-

2-

• • • • •

1.5-

• • • •

1-

*

05-

n

, * * * •

ELECTRICAL CONDUCTIVITY (dS/m)

POTASSIUM (mM)

1

20

17

14

11

8

5

2

Fij^. 3. Spatial (lisliil)uti()ii olaciiK'niis cxliactal)!!' aid il)ul(s lor 3 nioiiiids. Ma [loilion ol a iilaiit iaii()[)\ iiiliTii-ptcd llir
grid sampiintl pattern, it i.s listed in the plants panel in the n|)iiei- left-hand eorner S\inh()ls nsed; • = .A. occidcntdlis.
* = S. rcnniciildtits. and + = A. torreiji. Axes ()l'Krai)iis an- in m. All panels are oriented north (top) to south (bottom)-

Lalionl.iii l)asiii by Morrison (19(')4) shows lliat in llic Sii'ifa Xcxada cxiKnult'd tonsidcrahK

pedo.ucnesis since tlic middle I lolocciu' pro- ((Iniix 19(i9). Ilie late lloloeene coo\ and wt't

duces an o.xidized B liori/on. periods or neo^Iaeials contributed to the rise

The Holoceue in the western L'nited States in phi\ iai lakes (\h)rrison U)(i I). I leiuhls ol neo-

has been marked l)\ profound shifts in climate ulacial phi\ ial lake maxinunns are inicertain.

and vej^etation patterns (Antexs l93cS, l)a\is but in all likelihood water at times completeK

1982, WiKaud 1987, AucK-rson and Smith 1994). covered the F.a.^le \allc-\ embaxuient. iurther

The latest Holoceue has seen extended peri- reduciuu the potential a<j;e ol the moimds.

ods of drou,iiht lastinj^ >1()() yr (Stiue 1994) Neal and Motts (I9(i7) belief" that most ueo-

and cooler and wetter periods where glaciers mor|)hic features on and adjacent to |)la\as in

1998]

Plava Soil

227

4.5

4
35^

3
25

2
1.5-1

1

PLANTS

ELECTRICAL CONDUCTIVITY (dS/m)

* • •
• • •

POTASSIUM (mM)

JmiyHHjNIIBWMis —

1 1 1 1 1 T ' I

0 0.5 1 1.5 2 2.5 3 3.5

SODIUM (mM)

4i

'%

3.5-

3-

2.5-

' <^

2-

1.5-

fe^

/

1-

r

i

05
0-

1 1 'P'"'!'

1^1^

1

1450

1300

1150

1000

850

700

550

400

250

100

0 0.5 1 1.5 2 2.5 3 3.5
CHLORIDE (mM)

0 0.5 1 1.5 2 2.5 3 3.5
Fig. 3. Continued.

tlic western United States were formed within
the last 100 yr, a result of a lowered water table
eaused b\' man's activities. The most recent
glacial advance in the Sierra Nevada occurred
ifrom 1880 to 1908 (Cuiry 1969), which corre-
lates with rintis of A. occidcntalis in the stud)
area. Ph\ togenic hillocks can form and enlarge
in this time frame (Gile 1966).

Present osmotic potentials of these playa
margins are a magnitude too high for seed ger-
mination and suggest that large-scale plant
recruitment ma\ hinge on rare climatic events
(Romo and Haferkamp 1987, Blank et al. 1994).
\\'hat were those conditions in the past 90-120
\r that initiated mound formation? Present
plant recruitment occurs rarely in small, flood-
caused channels; howe\er. mound plant demo-
graph\- suggests pulses of large-scale recruit-
ment. If mound initiation began during a neo-
glacial cycle, then long-term increases in

eflfective precipitation may have leached solu-
ble salts deeper into the soil, thereby favoring
plant recruitment. This scenario is problem-
atic because long-term increases in effective
precipitation would promulgate playa flood-
ing. Perhaps plant recruitment on the playa
margin began at the end of the neoglacial
period. There would be greater sources of
unconsolidated material at the delta of the
Truckee Rixer for mound building. Moreover,
the neoglacial lake may have reduced the salt
content of sediments along the playa margin.

Do mounds provide benefits for plants or
are the\ happenstance, simpb' a result of in-
escapable ph\sical processes? Phreatophytes
such as S. venniculatus, which dominantly root
in the underKing lacustrine material, would
seem not to require mound formation for con-
tinual suni\ al. PotentialK beneficial aspects of
mound formation could include the following:

228

Great Basin Naturalist

[Vblunie 58

PLANTS

4-

•

•

•

•

3-

•

•

*

2-

•

•

•

*

1-

•

«

0

r—

ELECTRICAL CONDUCTIVITY (dS/ti)

POTASSIUM (mM)

1 2 3
SODIUM (mM)

BROMIDE (mM)

■1 1.08

4-

n 0.96

3-

0.72

2

^i^

0.6

0.48

0.36

.i^^^^

—

0.24

''^shP^

—

0.12

'^^^^

_^

0

0-J

— 1 — 1 — 1 — 1 — 1 — 1 —

— ' 1

1 2 3
CALCIUM (mM)

0 12 3
MAGNESIUM (mM)

0 12 3 4 5 6 7

Fig. 3. (.'oiitiniicd.

(1) a seecll)ed witli .superior pli\ sical cluiractt'r-
istics and lower salt content favoring the
recruitment of a host of plant species; (2) more
favorable rooting media compared to the dense
lacustrine sediments; (3) favorable bio-meteo-
rological properties in portions of the uu )uii(!
due to aspect, i.e., cooler soil temperatures in
midsunnner on the north side of the mound or
warmer temperatuies in earl\ spiiug on (he
south side of the mound.

At present, mounds liinclioii \ci\ pooiN as
seedbeds given the cxtiaoKhiiary levels oi salt
which would seem to iiegale benelicial aspect
1 listed ab()\-e. luirK' in the life histor\' of the
mounds, howcxer, they may have been far less
saline. 'I'hroughout this stud\' the sail content
of ri'ceiil coliaii sand d('|)()sils on large dune
fields and on die lee sides ol inoiiiids was

measured. Electrical conducti\ it\ \aliies ol
saturation e.vtracts were alwa\s below 4 dS
m~-, indicating no osmotic limitation for ger-
mination of seeds of native plants. In the \ears
of stud\', howex'cr, plant rt>ernitment was never
seen on the small eolian vcni't'r on the sides ol
mounds, possibly because the M-neers are too
thin to allow a rooting mantle. It appears, then,
that early in the lile history ol iiiouiids. ii-ciuit-
ment of plant species was not limited b\ salin-
it\. Because of e.xtreme periodicitv of mound
loiinalion, we are w itnessing mounds in Eagle
\'alle\ at an ad\aiu('(l age when e\trenu> salinitv'
prexciits new plant icciiiiliin'iil. .\s established
plants die, the no-louger-protected mounds
will erode and ni'w recruitment must await
the next rare mound-building phase. Inti'iest-
iiigK, soil deseiiptioii sites were i('\isiled in

1998]

Pi,AV\ Soil

229

July 1997. All soil pits, which wviv not coni-
pk'teK tilled in with soil, haxc had extcMisixc
rt'cruitnient of plants. One pit has ven' robust
plants of A. Irntijoniiis. and ,S'. rcnniciiJdtiis.

A(:k\()\\i,i.ik.\ii:nts

We thank Ms. Kay lilakeK and Ms, Clara
l^uitello of the U.S. Bureau ol .Mines lor exten-
si\e use of X-ra\- ditfraetonieter and interpre-
tation of X-ra\ didraetion data. The thorough
re\ic\v of a draft l)\ Dr. Jeanne Chambers of
the U.S. Forest Semce is greatK' appreeiated.
We thank the anon\nious rex'iewers tor insight-
hil eonnnents and eritieisins.

Literature Cited

Andf.rson, R.S., AND S.J. SNirni. 1994. Paleoclimatic inter-
pretations of meadow sediinent and pollen stiatii^ra-
phies from California. (k'olog\ 22:723-726.

.\NTEVS. E. 1938. Post-phnial climatic xariation in tlie
Soiitlnvest. American Mi'teorolotix Societx Bulletin
19:190-193.

Batwoinv, K.H., am:) M.I I. BArworw. 1968. Formation
oi phytogenic hillocks. 1. Plants forming ph\togenic
hillocks. Acta Botanica .^cademiae Scientiarum Hun-
garicae 14:24.3-2.52.

Bendali, E, C. Floret, E. Le Floc'h, a.\d R. Pontanier.
1990. The dynamics of vegetation and sand mobilit>'
in arid regions of Tunisia. Journal of Arid En\iron-
ments 18:21-32.

Billings, VV.S. 1945. The plant associations of the Carson
Desert region, western Nevada. Butler L'ni\ersit\
Botany Studies 7:89-123.

Blxckwelder, E. 1931. The lowering of pla\as b\- defla-
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230

Great Basin Naturalist

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Received 17 April 1997
Accepted 11 September 1997

CriMt Basin Naturalist 58(3), © 199S. pp. 231-244

WINTER MACROINV Ein EBIUTE COMMUNITIES
IN TWO MONTANE \\YOMIN(; STREAMS

(Miristoplici \I. Pc'iiiiuto'-, Frank dc\()\ellt'S, Jr. ', Mark A. (^omacP'',
IVank A. Vertucci'^ •^, and Sharon L. Dew c\ ''

Abstiuct. — Mac'r()in\ crtt'liratc coniiminities were exaniineil on 4 winter dates over a 4-yr period in 2 lii^li-altitude
i\iiek\ Mountain streams to doeunient o\ei\\intering assenihla^es potentially experiencing spring acid [)nlses. Taxa ricli-
ncss \alnes were comparable to other pnl)lished lists for alpine and montane stream s\'stems despite the fact that most
iiliiature reflected summer collections. Mean henthic densit> ranged Irom 1406 to 19,734 organisms/m-, and drift rates
r.iiigetl irom 0 to 1740 orgauisms/lOO ml ik-ntliic collections showed higher tirxa richness than drift collections while
till- Eiihcmeroptera and Plecoptera occurred in greater proportions in drift than in hcTithos. The Nemoiu'idae (Ple-
copteral, Kphcmeri'llidae and lli'ptageniidac (Ephemeroptera), Chironomidae (Diptera), and Ihdracarina wen- the
numericalK dominant t;L\a in henthic collections. Grazer/scrapers and shredder/detritivores were alwa\s tlie numeri-
calK dominant functional feetling groups at all sites, composing 60-90% of the benthos. Predators, constituting appro.xi-
mateK 15% of the commimitN, occurred in the same relati\'e [iroportion at all sites on all dates. Winter macroin\erte-
brate conummities in these low-order, montane streams exhil)il high taxonomic licimcss and liciilhic densities as grt-at
a,s lo\\er-elc\ation nioiiiitain streams in the West.

Ki'ii words: coitiiniiuitti stnicttirc. ii inter collections, stream insects, functional jeedinsi s^roups. Wyoiniiii^. montane
habitat.

Stream ecolotiists arc intere.stcd in under-
standing the forces influencing comnuuiit)
.structure and composition. Howexer, seasonal
changes in habitat features might influence
the relative importance of forces structuring
stream communities (e.g., Peckarsky 1983,
Minshall. Petersen, and Nimz 19(S5). Wiens
(1977. 1981) argued that seasonal, multisite
data were needed to make accurate assess-
ments of communit)' structure and resource
use because of annual \ariation in population
abimdances within and among habitats. Harsh
winter conditions (e.g., extreme cold, deep
snowpack, ice cover) or the timing of insect
hfe cxcles often pre\ents stream ecologists
from sampling some connnunities on a sea-
sonal basis. Movnitain streams, in particular,
recei\e hea\\ snowfall, making most sites in-
accessible dining w inter months. Yet, w inter is
the longest season of the year in mountain alti-
tudes, retaining snow cover up to 7 mon.

Few studies have examined macroin\ erte-
brate communities during nu'd- to late winter

in mountain streams. Logan (1963), who sam-
pled ac^uatic insects biweekly through the
winter in Bridger Creek, Montana, found that
Trichoptera lan^ae dominated the benthic taxa.
Andrews and Minshall (1979) and Minshall
(1981) sampled monthly throughout the year
and found all connnon taxa during all seasons,
but at different abundances. Communities
sampled were dominated by grazer and collec-
tor functional feeding groups. Bruns and Min-
shall (198(")) also sampled through the winter
and showed an extreme change in winter niche
parameters for the predator guild of an insect
community in the Salmon Ri\er The\ sug-
gested that resource limitation (i.e., low pre\
numbers) in winter was a factor determining
spatial resource partitioning in this system.
Howexer, these studies all focused on stream
reaches at elevations below 3()()() m. Studies at
elevations exceeding 3()()() m have been re-
stiieted primarily to the warmer, open-water
season (Dodds and Hisaw 1925, Blake 1945,
Elgmorkand Saether 1965, Saether 1965, .Allan

'l^cpartimiU ol S\ steiiuitics and ICcoIoK), L'iii\ ersily (il Kansas, Liiwrence. KS fitt04.5.

-Present address: Environmental Sc iine( and Polii \ PrDUrani, I ni\i rsit\ of Sontheni Maine, Gortiam. ME 040.38.

^United States Forest Senice, Crntinnial Station. CcntrnTn.il, W'l S2().5.i

■'Present address: Wyoming Department ol i:n\in)nnKTital ynalily. Water Quality Division. 122 West 2.5th Street, Cheyenne, WY S2(M)2.

^Present address: ENSR Consulting & Engineerinj;. 430.3 West LaPorte Avenue. Fort Collins, CO 80.521.

''Kansas Apphed Remote Sensing Program. University of Kansas. Lawrence, KS 66045.

231

232

Great Basin Naturalist

[\blunie 58

1975, Short and W'ard 1980. Ward and BcMncr
1980, Bushnell et al. 1982, 1980, Ward 1980j.

Recent documentation of episodic acidifi-
cation in mountain streams of the western U.S.
(e.g., Wilhams and Melack 1991, \'ertucci and
Conrad 1994) suggests a need to understand
winter stream connnunities if we are to assess
potenticil impacts fiom snowmelt-related, spring
pH decHnes. Winter samples collected imme-
diately prior to any potential spring acid pulse
could provide a reference picture of stream
insect communities while reducing temporal
difficulties associated with comparisons to
later times of the year. Repeated, short-term
acid e\ ents may have severe cumulative effects
on stream communities in acid-sensitive
streams of the West (Kratz et al. 1994). Impacts
due to episodic pulses of acidity may reduce
streamwater acid neutralizing capacity, influ-
ence fish community stability in small streams,
and mobilize metals (Baker et al. 1996, Kiffney
and Clements 1996, Wigington et al. 1996).
Knowledge of winter community structure
might enhance our ability to understand these
episodic spring events. Our objective was to
document the winter macroinvertebrate com-
numity structure in high mountain streams in
Wyoming for a baseline reference in assessing
snowmelt-driven, episodic acidification. We
estimated winter benthic macroinvertebrate
and drift density, taxonomic richness, and
functional feeding group abundance for high-
elevation streams having extensive snow coxer.

Mkiiiods
Study Area

Two streams were selected for studx. West
Glacier Lake Creek (WGL) and North (Carbon
Twin Lakes outlet (NCT). WGL is located
within and NCT adjacent to the United States
Forest Sei^vice Glacier Lakes Ecosystem Exper-
iments Site (GLEES) (106°15'W longitude.
41°22'N latitude). (JLEES was established to
collect baseline and e.xperinieiital data loi"
assessing atmospheric deposition elfeels on
sensitive alpine and subalpine eeosxstenis
(Mussehnan 1994). An ui^slream and a down-
stream station were established on each stream
such that the upstream station was located
w itliin a geologiealK aeid-sensilixc zone.

Stations \\(; and Lli are located on \\'Gl>,
ri and T2 on NCT (Fig. 1). WG is al an eleva-
tion ol '3250 m and approximateh' 150 ni dow n-

stream from West Glacier Lake. LB, approxi-
mateh 2 km downstream from WG at an ele-
vation of 3163 m, is located approximately 100
m upstream from Little BrookKn Lake. Tl is
located at 3240 m elevation, approximately 75
m downstream of the easternmost North Car-
bon Twin Lake and within 100 m of treeline.
T2 is approximately 0.25 km downstream from
Tl at an elevation of 3230 m and 100 m down-
stream from the confluence of the eastern and
western North Carbon Twin Lakes outflow
(Fig. 1).

WG, LB, and Tl are 2ncl-order streams,
whereas T2 is a 3rd-order stream. Sul)strates
at all sites consist of boulder, cobble and
gravel. All sites are within forest habitat domi-
nated by lodgepole pine (Pinu.s coiifoiia) and
Engelmann spruce iPicca engcliiuinnii). Scat-
tered stands of cjuaking aspen {Popiilii.s tremu-
loides) also occur near LB. All sites contain
populations of brook trout {Salvelimis fonti-
nalis). WG, LB, and T2 exhibit perennial flow
while Tl experiences some zones of internut-
tent surface flow. The streams were saiiipled
on 4 winter dates (November 1989, Februarx
1990, 1991, and 1992).

Sampling Design

All sites except I^B were snow coxcned on
all sampling dates and recjuired tunneling to
reach the streams. We constructed 3 tunnels
at each site on each date 1)\ digging through
the snow to the stream banks and proceeding
laterally until we reached the streams. Occa-
sionalK, tunnels opened direetK o\cr the
stream. In such cases, we collected samples
only upstream from the tunnel to reduce sam-
pling bias associated w ith disturbance of the
substrate. Snow depth (cm) was measiued
Iron) the top of each tunnel to the ground.

On each date we took 3 Surber saniplc\s (1
sample per tunnc-1, 929 cm-. 280-)Lim mesh) if
water was present. All stones w ithin the sam-
pler were brushed to dislodge an\ organisms
and the snbstiate was agitated to a depth ol
approximateh 10 cm. Organisms were pre-
serxc'd in 800. EtOll in Whirl-Pac bags. In
I'ebrnaiA lf)91 and 1992. watei' was frozen or
ahsent in some tinmels at Tl resulting in 2
and I Surber eolleetioiis on those dates,
ic'speetixc'ly.

Alter eonipieling bentliie eolleetions. wc
placed I diil't nc-l (I X h X w : 100 X 30 X 46 em;
2S()-|.lni mesh) midstream in the npstream-niost

1998]

W i\ii;k SiKKAM C]()\i\ii \rrii-:s

233

Fig. 1. Location of 4 samplinu; sites in tlie Metiicine Bow
National Forest of sonthcast Wyoming.

opening for a dusk-to-dawn drift collection fca
12 h). Tunnels were eoxered with black plastic
and tarps to prevent overnight snowfall accu-
mulating in holes and to eliminate an\- possi-
l)ilit>- that starlight or difhise dusk/dawn light-
ing might influence drift patterns. Stream \ ol-
unie filtered was estimated from the product
of velocity, cross-sectional area, and duration
of net set. Average veIocit\' (Swoffer Model
2100 flow meter) and depth were based on 6
measurements, each from the mouth of nets
upon placement and retrieval. Total set-time
was recorded when nets were retrie\'ed. Sam-
ple drift densit\ (no./lOOnr^) was calculated
according to Allan and Russek (1985).

On each date we collected a single water
sample for chemical anal\ ses. Water tempera-
tures were taken w ith a hand-held thermome-
ter just prior to sample collection. Samples
were collected in dark, acid-washed plastic
bottles, laborator\ -filtered (Gelman 0.45-fim
glass microfiber filters), and split into an acid-
preserved (0.1 fll of 6.0 N nitric acid) and a
nonpreserxed subsample. Samples were re-
frigerated and usualK anaKzed within 48 h of
collection. All samples were analyzed by the
United States Forest Senice Water Chemistn-
Laboraton in Fort Collins, CO. Major anions
and cations were estimated on a Dionex 2010i
ion chromatograph. Cations were also verified

234

Great Basin Natlir.\list

[Volume 58

with a Sinith-Ilic'ltja 22 atomic absorption
spectropliotomettT. C'onductix it) was mea-
sured with a YSl conductance meter (Model
32). Acid neutralizing capacity (ANC) and pH
were determined using an ARAS (Acid Rain
AnaKsis S\stem) radiometer.

(>()iiinnmit\ AnaKsis

Macroinxertehrates were identified to the
lowest possible taxonomic unit (usually species
for insects except Diptera) using the following
taxonomic keys: Allen and Edmunds 1962,
Jensen 1966, Smith 1968, Edmunds et al. 1976,
Baumann et al. 1977, Pennak 1978, Szczytko
and Stewart 1979, Merritt and Cummins 1984,
Klemm 1985, Peckarsky et al. 1985, Stewart
and Stark 1988, and Ward and Kondratieff
1992; also G.T. Baxter, University of Wyoming,
unpublished manuscript. Some taxa were veri-
fied by comparison to the Kansas Biological
Survey (KBS) Reference Collection, to which
new records were added. Functional feeding
group designations followed tables in Merritt
and Cummins (1984).

Results

Data from November 1989 samples are
omitted from an\' comparisons across years
due to potentially confounding time effects.
However, the November 1989 data are illus-
trated for completeness.

Physicochemical Analysis

Snow depths ranged from no co\'er (at LB
in all years) to a maximum oi 290 cm at WC in
1990 (Table 1). Generally, the 2 higher-eleva-
tion sites (WG and Tl) had deeper snow cover
than the 2 lower-elevation sites (LB and T2).
Morning and evening water velocities were
typically within 5 cm/sec of each other (Tabic
1). The iiiininiinn (lillcrcnce recorded was 0.3
cm/sec at 12 in 1992, the maximum 5.3 cm/sec
at W(; in 1990. Water depth rareb exceeded
10 {III. Siirlacc ice was encomitered only at '\\
in 1991 and 1992, although all sites contained
botli anchor and frazil ice in \ar\'ing amounts.
Water tciiipcratiire ranged bom ()..>' to LS ( !
riablel).

Ml sites were tliaiacteiized l)\ eirciimiieu-
Iral 1)11 \ahies Clliblc- 2). WG had the lowest
pll readings while LB always had the highest
pH, ANC, and conductivity values. Mean con-
ducti\'ities ranged from 30.2 fiS/ciii al Tl to

138.0 |aS/em at LB. Xhijor cation and anion
concentrations \aried across years and sites.
Calcium and magnesium levels were 3—5 times
greater at LB than at the remaining sites while
anion levels were similar across sites and low-
est at WG (Table 2).

Connnunit) Analyses

Of the 56 taxa we identified, no taxa
occurred at all sites on all dates. 1-lichness was
greatest at LB in all \'ears and lowest at Tl in
all years (Appendix). Three sites (WG, LB, and
T2) showed low year-to-year variation in rich-
ness values (CV' = 10.4%, 9.8%, and 13.6%,
respectively), whereas yearly variation in rich-
ness at Tl was higher (CV = 41.1%). Richness
ranged from 9 (Tl in 1992) to 41 (LB in 1991).

All sites contained representati\es of the 4
major fimctional groups. The grazer/scraper
guild varied most annually (CV = 63.7%),
whereas the predator guild varied least (CV =
25.1%). Grazer/scraper and shredder/detriti-
vore groups dominated all sites; collectors
were always least abundant (Fig. 2). Collectors
represent the combined numbers of collec-
tor/gatherers and collector/filterers. Predators
comprised approximateK' 15% of the commu-
nities at all sites on all dates.

Diptera composed the greatest proportion
of the benthos (i.e., no. of Diptera in benthic
samples/total no. in benthic samples) in all
years at all sites except that in 1990 at T2
Ephemeroptera were highest (Fig. 3). On
average, Nemouridae (Plecoptera), Baetidae
(Ephemeroptera), and il\(lracarina were the
other numerical dominants in the benthos
(Appendix). Few taxa were found al all siti's on
all dates. The most ubicjuitous taxa included
Plecoptera {Swcltzd Uiuihd. '/Aipada luiysi, and
Z. r///r///n'.s), EphenicropttM-a (Ephoiicnlld
ntjn'ijiwns, Ciny<!,inul(i sp., and Bdctis hictnida-
tus), and Trichoi^tera {Rlu/dcophild hrninud and
li. vcmild; .Appendix). Se\-en ta\;i [rluniiixrid
(lii'crsd. Pdrdlcuiird rcrshiiuL :\.r(l()i)\ijclic
<:,rdii(li.s, lilii/dcopliild pcllisd. ANf/i,v//)c///.v sp.,
Lcpidosloiiid sp. , and OliLioplilclxxlcs iiiiinitiis)
were collected oiiK hoiii LI?. IViclioiitcra
alwa\s accounted lor <!()'< ol the bciilhic
c'()mmuiiit\.

I)ipter;i and l'.|)lieiiu'r()ptc'ra compiisccl the
greatest |)i"opoitioii ol drilting taxa (e.g., no. ol
Dijiteia (Iriltiiig/total no. drilting), whereas
IVichoplcra and 1 1\ ciracariiia constituted the
least (Fig. 1). Pro|)oiiioiis ol F]ilic'iiic'i()ptc'ia |j

1998]

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236

Great Basin Naturalist

[Volume 58

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grazer/scraper

WG LB

predator

shredder/detritivore

60 ^^

T2

WG LB T1 T2

collector/gatherer

(U 40

Site

Fig. 2. Relative percent composition of functional feeding groups in the benthos during winter inontlis in 2 mountain
streams. From left to right, bars reflect samples collected in November 19S9. Febnian 1990, 1991, and 1992, respecti\eK.

O

a,

B
o
o

-4->

c
<u
o

V-c

(U

a,
<u
_>
•*— >
i2
<u

Diptera

kiiiii

Ephemeroptera

WG LB

Hydracarina

LM, *■

WG

90 I Plecoptera

60

LB

WG Lli

90 Trichoptera

WG LB

Site

Fig. 3. Relative percent composition oIulijoi- orders in llic ixnliins IVom Idl In riiilit. Ii.ns iclleit saiiipii
in November 1989, ['ebruaiT 1990, 1991, and 1992, respeelixeK.

vied

1998 J

W iMEH Stream Comml mties

237

and Plecoptera in drift samples exceeded heii-
thic proportions while Diptera occnrred in
lower proportions in the drift relative to ben-
thos. Ilydracarina and Triehoptera were
appro\iniatel\ e(|nall\' represented in benthos
and drift (Figs. 3, 4).

The mean nnmber of organisms in the ben-
thos (no./m-) ranged from <15()() to >15,()()()
organisms (Fig. 5). Chironomidae were always
the most numerons. Sample drift densities
generally ranged from 100 to 600 organisms
per 100 ni'^ and showed no consistent pattern
across sites or times (Fig. 6).

Dlscussion

Unlike other faimistic stndies in monntain
stream habitats, this stnd\' examined macro-
in\ertebrate communities in 2 high-elevation
streams under winter conditions. Taxonomic
richness observed in this study was slightly
higher than sunmier faunal sur\ eys from other
western mountain streams (Ward 1975, 1986j.
As expected, the highest richness values were
fovmd at the lower-ele\ ation sites LB and T2.
.\lso, the 3 sites with permanent water flow
exhibited lower annual variation in richness
values (CV's < 15%) than Tl, which had no
flow on 1 of 4 dates. Community composition
was similar to that recorded b\ Kondratieff
(1994) during a (jualitatixe sunmier collection
of atjuatic macroinvertebrates from lakes and
streams in the GLEES area. He collected 72
taxa during that stud\. While this represents
16 taxa more than we collected during this
stuck, his collections focused on littoral zones
of lakes and streams and were made during
summer months. Our samples were all col-
lected during winter from streams only and
within midstream microhabitats.

I'lmctional feeding groups in these streams
duiing winter were compositionalK' similar to,
\ et proportionalK' different from, sunmier col-
lections in other mountain streams and fit well
with expectations of an expanded river contin-
uum concept (RCC; Vannote et al. 1980, Min-
shall et al. 1985). We found the grazer/scraper
guild present in higher proportions and collec-
tor/gatherers in lower proportions than might
be expected for low -order, eastern woodland
streams, which are expected to be heaviK
shaded by riparian canopies that limit autoch-
thonous food resources (Vannote et al. 1980).
However, new sxntheses of the RCC incoipo-

ratc the effects of local litholog\/geomorphol-
()g\ on insect coniniunit\ de\elopnient. These
high-elevation streams are near the treeline in
relati\el\ open woodlands where potential
autochthonous production is expected to be
high, offering ample food resources for the
grazer/scraper guild. These patterns suggest
that the IK'C predicts well for the grazer/
scraper guild in high-ele\ ation westeni streams.
Further stuch is warranted on these streams to
correlate grazer/scraper abimdance with algal
pr()ducti\ it\ under winter conditions.

Shredders were the other dominant func-
tional guild, composed primarily of nemourid
stoneflies. This contrasts with results of Short
and Ward (1980) for a stream of similar alti-
tude (though a sununer stud)) in which shred-
ders constituted a much smaller percentage of
the benthos, but were still primarily nemourid
stoneflies. Their study site flowed through a
meadow while our sites were principally
within forested reaches, potential!) offering
higher (quantities of allochthonous material for
shredders. Also, our functional guild is a mix
of shredders and detritivores. Possibly, the
detritus feeders dominate these sites and the
shredders are of less importance.

Proportions of the major insect orders were
similar to nian\ other mountain stream studies
(e.g., Saether'l965, Allan 1975, Ward 1975,
1986, Short and Ward 1980, Minshall 1981),
even though most studies reflect summer col-
lections. Diptera (primarib Chironomidae) and
Ephemeroptera were alwa\ s the most numer-
ous taxa in our study. In general, Ephemer-
optera and Plecoptera occurred in greater pro-
portions in the drift than in the benthos while
the reverse was obserxed for the remaining
orders, indicating that nia>flies and stoneflies
are more prone to drift than the remaining
ta.xa. Howe\ er, drifting nia\flies and stoneflies
were predominantK earl\ instar Baetidae and
Nemouridae, suggesting that these 2 groups
are winter active or more susceptible to pas-
six e drift than the remaining taxa.

H\ (Iracarina often exceeded Plecoptera and
Triehoptera in benthic abundance, an occur-
rence not generally reported. Because other
faunal surveys, based primarily on summer
collections and focusing on insects, have not
included the Hydracarina, comparisons are
difficult to make. However, failure to include
the Hydracarina in community analyses will
overemphasize proportions of remaining

238

Gkl;ai- Basin Natl iulist

90 Ephemeroptera

[\blume 58

WG LB

o

^ 90 Hydracarina

6

o

O 60

■t— >

c

OJ 30

(U
.^ 90

"OJ 60

30

0

WG LB

Trichoptera

30

0

WG LB

90 ^ Plecoptera

60

30

0

Site

Fig. 4. Relative percent composition of major orders in the drift. From left to riiilit, bars reflect sanipk's collcited in
November 1989, Febman- 1990, 1991. and 1992, respecti\t>I\.

WG

jc 5

Nov 89 Feb 90 Feb 91 Feb 92

Nov 89 Feb 90 Feb 91 Feb 92

Nov 69 Feb 80 Feb 91 Feb 92

Nov 69 Feb 90 Feb 91 Feb 92

Date

Fig. 5. .Mean (it — .3) densitx of bi-ntliic or^ani.sms (no./m-). Only 2 and 1 samples witc c()1I(
1992, respectively. Error l)ars are +.sy.

led lor II ni \m\ an

comiminity nieinhcrs. .Mo.st Hydracarina arc Total (k-nsitx olhciitliic oruanisnis in these

predator) as adults or parasitic as lar\ac (Pen- sticains was ncia liiuli compared to otlu'r nioiiii-

iiak 1978) and nia\ lia\c siji;nilicant impacts on lain streams ol similar altitnde (Slioi I and t

macroinvertehrate nnmhers. Drift estimates Ward lUSO) hnt eomparahle to estimates madi'

chanj^ed little witli or witliont inclusion of the l)\ \linsliall (19S1) in a lowcr-altitnde stri-am

I h'dracarina. reach. llo\\c\ci-, mesh sizes in all onr nets

1998]

\\ IMKK STIUZAM C(X\IML MTIES

239

I ^ WG J l.i^

+

% " No\ 89 Feb 90 Feb 91 Feb 92

No\ 89 Feb 90 Feb 91 Feb 92

I'isi. 6. Sample drift tlensih dio./lOOm') for all organisms.

were consideial)l\ smaller than those used h\
Short and \\'ard (280 JLlni in our study vs. 700
Uni in theirs): thus, the ranue of sizes eaptured
was greater. Ma.xiniuni densities e.xeeeded
1.5,000 organisms/m- on some dates, but were
usualK nearer 5000/m-. We e.xpected low
organism abundanee during our winter sam-
pling beeause egg diapause was a suspected
life histoiy attribute of some communit\' mem-
bers, especialK within the Trichoptera and
Ephemeroptera (e.g., see tables in Merritt and
Cunnnins 1984). The great abundance of small
(< 2 mm) Baetidae (Ephemeroptera) during
.\o\ember sampling suggests the)- ha\e a
short incubation period prior to luitching.
Minshall fl981) also reported the Baetidae
occurri'd in high abundance during winter
months in an Idaho stream.

Densih' of drifting organisms was not par-
ticularK high relati\e to summer drift collec-
tions in other high-ele\ation streams (Allan
1987). Because we did not record diel period-
icitx in drift, it is hard to ascertain whether
this proximal cue is important during winter.
In fact, under prolonged darkness it is possi-
ble that drift is eciually abundant at all hours
of day and night. Extended periods of dark-
ness may reduce insect susceptibilit> to pre-
dation b\ \isual-feeding fishes, resulting in
high drift densities. Likewise, drift rates might
be high if encounters with predaton inxerte-
brates increase (Peckarsk'^ 1980, Soluk and

Nov 89 Feb 90 Feb 91 Feb 92

I T2

hiii

No\ 89 Feb 90 Feb 91 Feb 92

Date

Collins 1988) because the predators are also
released from fish predation constraints.

This stud}' pro\ides a preliminary assess-
ment of winter macroin\'ertebrate comniunit\
structure in high-ele\ation streams and sug-
gests that winter communities are di\erse and
numericalK abundant. Though Xertucci and
Conrad (1994) documented spring acid pulses
in some glacial-melt headwater streams of
GLEES, winter pH in our sites was circum-
neutral, indicating that pH depressions do not
begin until early snowmelt. Similarly, the
macroinvertebrate community composition
was not indicative of one stressed by acidit\.
Further studies comparing these communities
in different seasons ma)' pro\ide insights to
the role of seasonal heterogeneitx in conunu-
nity ecology.

Although winter stream conditions are harsh
(i.e., extreme cold, reduced flow, lack of sun-
light), there ma\ be less \arial)ilit\ in key abi-
otic parameters during this season than at
other times of the year. For example, stream
flow and temperature are 2 critical features for
acjuatic insect ecolog) and biolog\ (Ihiies 1970,
Ward 1989). Variation in stream discharge and
xelocity during winter is minimal because
cloudbursts and thaws, which ma\' lead to rapid
discharge increases, do not occur. Temperature
fluctuations are also minimized because there
are no direct effects from solar radiation as
streams are snow coxered. These obserxations

240

Grkat Basin Naturalist

[Volume 58

su^urst that winter nia\ be a time wlieii physi-
eal habitat features exhibit low temporal het-
erogeneity (sensu Kolasa and Rollo 1991) and
may influenee winter eommunity strueture.
Likewise, the reeent documentation of episodic
acidification associated with spring; snowmelt
in the West (\ertucci and Conrad 1994) sug-
gests a need for greater understanding of win-
ter connnunitv' structure. A knowledge of over-
wintering connnunities will help us accurateK
assess the effects of these episodic events.
Also, seasonal comparisons of community stioic-
ture and function and a detailed focus on win-
ter stream d>'namics may fiuthei- our under-
standing of the forces important in structuring
stream communities.

Acknowledgments

We are grateful to E. Maurer, S. Swaffar,
S. Langley-Turnbaugh, and 2 anonymous re-
\'iewers for comments on early drafts of this
manuscript. The research was funded in part
by Kansas University GRF Grant #6363 to E
deNoyelles, Jr., and a Sigma Xi Grant-in-Aid
to G. Pennuto. R. Musselman and L. O'Deen
of the U.S. Forest Service provided lodging
and water chemistiy analysis, respectively.

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Received 26 June 1997
Accepted 22 October 7,9.97

The appcndi.x follow s on the ne.xt 3 pa^cs.

242

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RANGE OF rili: BKOWN-HEADEDCOWBIRD
IN COLOKADO: R\ST AND RRESENT

Janicsoii K C;hac'f' and AlrxaiuU'r Cruz'

Abstr.XCT. — The historic range of the bison (Bison bison) on the (weat Phiins has been well docnmented. In Colorado
the range of bison included both the eastern grasslands and higher-elesation ridges and mountain parks, up to an eleva-
tion of 3900 ni. Based on the commensal relationship of the brood-parasitic Brown-headed Cowbird {Molothrus ater)
N\ ith the bison, we suggest that the cowbird had a larger historical elevational range in Colorado than pre\ iousK' known
and c()nM'(|utMiti\ has had a long-term host-para.site relationship with high-elevation breeding songbirds.

Kiij words: Broil n-lu'(i(U(l Coul>ir(l. Moli

liter, I>i.soii. Bison bison, r(Ui<:,c expansion. Colorado.

The Brow n-lu-adecl ('()\\l)ir(l (Molothru.s
ater) i.s a well-studied oi^li^ute brood para.site
(Roth,stein 1975. Friedinanii et al. 1977, Rodi-
stein 1990, Robin.son et al. 1995, Cook et al. in
pre.ss) that hi.storiealK oeeiipied a range similar
to that ot the bison {Bison hison; Friedmann
1929). Cow birds ranged oxer the Great Plains
in eonnnensal assoeiation with bison; these
"buffalo birds" are thought to have foraged
among the grazed grasslands for inseets stirred
up b\ herd moxements (Friedmann 1929, May-
field 1965). They later expanded their range
w ith the clearing of forests and introduction of
domestic livestock (Ma\Held 1965, Rothstein
1994). In Colorado, Brown-headed C'owliirds
ha\e undergone a recent ele\ ational range ex-
pansion, possibly due to habitat alteration and
cattle grazing in the high countn' (Hanka 1985),
similar to cowbirds in the Sierra Nevada Range
(Rothstein et al. 1980, Rothstein 1994).

The historical range of bison on the Great
Plains is well documented (Allen 1877, Roe
1970). In addition, bison in the Rock") Moun-
tains historicalK ranged above timberline in
Montana, Wyoming, and Colorado (Fr\'xell
1926, 1928, Warren 1927, Beidleman 1955,
Pattie and Verbeek 1967). Bison once ranged
throughout most of Colorado west of the Great
Plains and at all ele\ations (Armstrong 1972,
Meane\ and \an Wuen 1993). Furthermore,
bison probably were relativeK' abundant
throughout northwestern Colorado, South
Park, Middle Park, North Park, and the Front
Range C\niistrong 1972, Meane\ and Van Vmen

1993). We suggest that because of their com-
mensal relationship cowbirds also occurred at
high ele\ations in Colorado until their range
contracted with the extirpation of bison and
that the\' have undergone an elevational range
re-expansion with the introduction of domestic
li\estock.

Our puipose is to demonstrate that (1) the
1st observations of cowbirds in Colorado
occiuTcd during the time lapse between extir-
pation of bison from, and movement of cattle
into, higher elevations, and (2) the number of
high-elevation records of cowbirds increased as
the number of cattle in the w^estern counties
increased. Implications of long-term host-para-
site interactions in Colorado s high-ele\ation
region are discussed.

Methods

We reviewed records of cow bird parasitism
(see Chace and Cruz 1996) and bison distribu-
tion and determined the tinnng and abundance
of cattle introductions to the C'olorado counties
west of die Great Plains. We iilso reviewed Colo-
rado agriculture statistics to obtain the number
of cattle in each count\' per year from 1883 to
1985 (intermittent xears missing). Colorado
counties east and west of the Front Range were
analyzed separately, with Front Range counties
containing >40% grassland habitat designated
as eastern (see Fig. 1 for delineation of coun-
ties). Cattle numbers were summed per year
b\ eastern and western designation. Although

'Department of En\ironniental, Population, and Organisniic Biolog\. Lni\ersit\' of Colorado, Boulder, CO 80309-0334.

245

246

Great Basin Natlh\list

[V'olunie 58

50

100 Miles

50

100

1 50 Kilometers

Fig.l. Recent distrihiitioii ol hison {Bisiin bison) in (Colorado witli emphasis on tlie I'e^ion west ol tlie Cireat Plains,
Solid circles represent specimen localities. Open circles represent localities extracted from literatvne. C^entral line delin-
eates Colorado counties west of the (heat Plains. Map and information taken from Meane\' and \'an Vuren (1993) with
permission ol the l^enver Mnseum ol Natural llistor\'.

cattle arc not tlic onK' livestock that attract cow-
hirds (Kotii.stciu et aj. 1980), tliey are hy far the
most numerous and probably are a good indc.\
of livestock numbers per comity in general.

liK.srixs

Meaney and Van Vuren (1993) recorded all
known bison specimens in Colorado west ol
the Great Plains from which we calculated that
of 116 bison specimens, 56.9% were collected
above 2500 m (Table 1). Recent research on
free-ranging bison has shown that bison haxc
seasonal elevational moxcments through open
l)on(lerosa pine iPituis pDudcrosd), pinon-jum-
\)vy uoodlands iP. monoplii/lhi and Jiiiiiix'nis
scopiilontin), and across subalpiiie loiest-i)ark-
land habitat (Fuller 1962, Van Vuren 1983, \an
Vuren and Bra\ I9S6, Shaw and Carter 1990).

Furthermore, based on specimens taken (Fig-
gins 1933), some herds of bison w intered in die
mountain parks and uugrated into higher ele-
\atious through forested couununities during
the sununer (Meanc)' and \'an N'uren 1993).
Extant free-ranging bison in forested montane
habitat of the Henr\' Mountains of Utah haw
smaller group sizes (2-30 animals) and largi-r
home ranges (52 km-) than bison of the Great
iMains (Van \ureu 19S3, \'au \ureu and Hra\
1986, Meane\ and \an \ men 199;5). In Colo-
rado. Renediel (1993 pc-rsonal conununieation)
speculates that bison wc-re c-\tiipated Irom the
F.sles l\iik area l)\ 1 S59 primariK due to tlii'
( rfccls ol the harsh wintc-r of 1813-41. 'I'hat
wiiilci. ill combination with market himting,
iiia\ ha\c been the cause ol !)ison decline in
other |)ails ol the state. I'he last known wild

1998]

COWBIKI) UWCK Exr.WSlON 1\ CoLOiUDO

24'

'l"\m.i: 1. Klf\ati()nal distribution of bison specimens in
22 Colorado counties west of the Cireat Plains (from
Meane\ and \'an \'uren 1993).

No. ol

spccimcTis

Ele\ation (m)

{N

= 116)

3501 +

13

3001-3500

21

2501-3000

32

2001-2500

36

1500-2()()0

\\

bison ill Coloriulo were killed in lS9i in l^ark
Count)- (Con- 1912), although a few may have
snr\ i\ecl until 1904 (Wiirren 1906).

Bison numhers were \ en low In 18(S3 when
eattle were fairK abundant east of the Conti-
nental Di\ ide in Colorado (268,585 head), witli
eonsiderably fewer in the western eounties
(56,782 head; Colorado Department of Agri-
culture. Colorado Agriculture Statistics, 1883-
1985). NearK' equal numbers of cattle occurred
ill eastern and western counties through the
192()s (Fig. 2). Western counties reached their
present lexels of cattle population by 1959, w-itli
a peak in 1974 (829,300 head; Fig. 2). From
1941 the number of cattle in eastern counties
consistentK- was double the number west of
the plains, \\ ith a peak in 1973 of 2.978,800
head (Fig. 2).

Records of co\\bird parasitism or presence
rarely mention exact elevational localities. Early
naturalists in Colorado sur\eyed high eleva-
tions and found cowbirds primariK occurring
in grasslands and foothills below 2500 m (Hen-
shaw- 1875, Drew 1885, Giile 1893, Cooke 1897,
Sclater 1912). More recently, cowbirds have
been noted at higher eiexations. Keeler-\\blf
et al. (1972) reported parasitism of a Yellow
Warbler {Dendroica petechia) nest in Gunnison
Count)- (2895 m). Cowbirds were common in
mountain parks and rixer valleys in 1977 and
1978, with obsenations up to 2890 m in Park,
Lake, Jackson, and Larimer counties (Hanka
1985). From 1986 to 1989, 164 Brown-headed
Cowbirds were trapped and banded at a feed-
ing station on Mt. E\-ans (elexation 3260 m).
Cowbirds were trapped from April to August,
with highest numbers in Max (mean = 29.0);
males outnumbered females 2.35:1 (Loiraine
E. Reiner unpublished data). Hanka (1985) re-
ported parasitism of Brewer's Blackbirds
{Euphagiis cyanocephahis) at 2895 m in north
central Colorado. Spencer (1985) reported an

3000.0-|

s>

2500.0-

n

Canlc in (he east

°^

•

CatUe in the west

^ w

2000.0-

DD

1500.0-

D

1000.0-

^ ^W

^

500.0-

^S

^

^y^

0.0-

•

— I 1 1

Kig. 2. Numher ot cattle in eastern and western Col-
ado (1SS3-19.S5).

adult Wilson's Warbler (Wil.sonia pttsilla) feed-
ing a )()ung cowbird at 3180 m. Wilson's W'ar-
blers were also reported to be parasitized in
Boulder, Clear Creek, and Sununit counties
(Elisabeth Amnion unpublished data). In
1993-94 cowbirds parasitized \\'arbling Mreo
(Vireo gilviis) nests ca 3000 m in Boulder
Count)' (Chace impublished data). Recently, a
number of high-elevation records of parasitism
have been reported in the Colorado Breeding
Bird .\tlas project (Table 2; Colorado Breeding
Bird Atlas unpublished data).

Discussion

In Colorado, cowbirds jirobabK- had a his-
torical, geographical, temporal, and elexational
distribution similar to that of the bison, with an
upper elevational limit ca 3800 m. Bison prob-
abl\- were numerous enough in the mountains
to support commensal flocks of cowbirds dur-
ing the avian breeding season. As the bison
approached e.xtiipation in the mid-18()0s, herds
were small and scattered, and cowbirds would
have been mostl)- restricted to lower ele\ ations
w here cattle were just i:)eginning to show appre-
ciable numbers in Colorado (Fig. 1). Cowbirds
likel) became associated with cattle in eastern
(>()lorado and began to re-e.\pand their range
follow ing the growing cattle herds to the west.
By the turn of the centun; naturalists began to
record a\ ian distributions in Colorado. Even
though higher ele\ ations were suneyed (Drew-
1885, Sclater 1912), cowbirds were found pri-
mariK' fi-om grasslands to foothills and mountain

248

Great Basin Naturalist

IXbkiuu' 58

Table 2. Records of covvbird parasitism from western liif;li-e!e\ation counties from tlie Colorado Breeding Bird Atlas
(1987-1994).

Species

Years

Countit

Willow Fl\ catcher {Kmi)i(hm(ix trailii)
Dusk) Flycatcher {Einpulonax ohcrliaheri)
Cordilleran Fl\ catcher {Ein))i(I(>nax difficilis)
Hemiit Thrush {Cutharus ^itttatiis)
Warbling V'ireo {Vireo giliits)
\'irginia"s Warbler (Veniiiiora lir^iuiae)
Yellow Warbler iDcndroica petechia)
■^'ellow-runiped \\;irbler (Dendroica cownaia)
MacCiilK ra\ s Warbler [Oporonm tolmiei)
Wilsons Warbler (Wilsonia pusilla)
Green-tailed Tow hee iPipilo chlontrus)
Fox SpaiTow (Passe reiki iliaca)
Song Sparrow (Melospiza melodia)
Lincoln Sparrow (Melospiza liitcolnii)
Gray-headed Junco (Jiiiico hyeinalis)
Brewer s Blackbird (Eupha^us cijanocephalus)

1987

Jackson

1994,
1991

1995

Jackson, Eagle
Teller

1990.

1994

Park. Mineral

1988.

1993.

1994

Guimison, Fremont. Montrose

1994

Teller

1987.

1993.

1994

Grand, (iuunisoii. (ackson

1991
1994

Routt
Gunnison

1988

Simimit

1991,

1993

Routt, Montrose

1993,

1994

Eagle, Grand, Summit

1995

Teller

1994

Park

1991,

1993

Grand, Gunnison

1991

Gunnison

parks, <25U0 m (Henshaw 1875, Gale 1893,
Cooke 1897), although Friedmann (1929) re-
ported an ()l).ser\'ation of a female eowbird in
a.ssociation with horses at 2895 ni in Colorado.
It was not until 1958 that the total number of
cattle in Colorado rose above 2 million head.
After 1958 cattle numbers remained high and
stable in western counties, while the number
of cattle would double in eastern counties by
1973. Shortly after this time, cowbirds were
found breeding at high elevations, ca 2800 m
(Keeler-VVolf et al. 1972, Hanka 1985). These
data suggest that Brown-headed Cowbirds
occurred at high elevations in Colorado until
the extirpation of bison and have recently
regained their former range with introduction
oi domestic li\ estock.

In Colorado the center of bison abundance
was the eastern grasslands. Although bison
have been recorded in high montane areas in
central and northwestern Colorado, records
are conspicuously absent from the southwest-
em comer of the state (Meaney and Van Vmcn
1993). C'owbirds are known front the eastern
portion of the state, but little is known about
their distribution in the west prior to the bison
e.xtirjxition. 'Hiey probably were located along
the major tributaries to the Colorado Hi\t r
(Rothstein 1994) and were associated with
western bison herds. I'ollowing cattle introduc-
tions, western populations of cowbiids may
also lia\c' re-expanded their elcxationa! dislii-
bnlion; however, a distributional change lias
not been well documented. In all probabililx
the elexational range re-expansion was biiiiodai.

but more pronounced along the eastern edge
of the Rocky Mountains.

Prior to the extirpation of bison in the mid-
1800s, Brown-headed Cowbirds undoubtedly
bred and parasitized the nests of many song-
bird species in high-ele\'ation regions of Col-
orado. It is likeh' that eowbird numbers at
higher elevations declined as bison were extir-
pated and resurged following the introduction
of cattle. However, now a different pattern of
eowbird parasitism probabh exists. When cow-
birds h)llowc'd nomadic bison herds, their para-
sitic efforts and eggs were dispersed o\ei- the
range of seasonal movements of bison herds,
whereas now eowbird iireeding populations
are as stationaiA as the herds of li\ estock around
which the\ forage. Implications of this chang-
ing pattern on songbird comnumities are likeh
ver\' important. Where once songbird coiiunn-
nities ma\' ha\e encountered brood parasitism
lor onK a jMJrtion of their breeding season,
now the pressnii' of parasitism is pronoimced
tiiroughout their icprodnctixe effort. In addition,
because of the strong sitc> fidelit\ of nian\ song-
birds (Greenwood and llar\t'\ 1982, Holmes
and .Sherr\ 1992), parasitism pressure ma\ exist
throughout the liletime rcprodnctixc- eflort of
mau\ individual birds.

At:i^\()\\ Li.i)(.\ii;\rs

Initial concepts for this paper came through
tliouglilini discussions with jim Benedict. We
(liank fx)rraine K. Heiner and I'lisabcth Annnon j
lor sharing their nnpublislied data with us.

1998]

CowniHi) Ha\(;k Iv\I'v\si()\ i\ Colorado

249

Comiiients made I)\ (>.H Ortciia, A.I). Bt-nc-
clict. J.B. IkiK'dict, D.M. Anustronu, II. KiiiiiciA,
C.A. McaiK'N, and 2 anoiniiious rex icwcrs on
earlier drafts are greatK appreeiated.

LlTER.VTlRE ClTl'D

,Al.l,l£\, J.A. 1877. Histon' t)l the .Viiifricaii hison. Bison
americanus. Annual Report o\ the I'.S. Ceolo.^ical and
Geographieal Sune\,s of the Territories 9;44.3-.587.

AkmsTKoNc;. D.M. 1972. Distrilnition of'maninials in Col-
orado. Monograpii of the Uni\ersit\ of KaTisas Muse-
um of Natural Histoiy 3:1—415.

Bkidlkman, H.C;. 19.55. \n idtitudinal record tor hison in
northern (Colorado. Journal of Maninialog\ 36;
470-471.

Benf.DK T. J.B. 1993. K.xcavations at Bodes Draw, a
women s work area in the mountains near Estes Park,
Colorado. Research Report. Center for .Mountain
Arclieolog)- 6: 1— i2.

CiiACE, J.E, AND A. Cruz. 1996. Kiiowlediie of the Col-
orado host relations of the jiarasitic Brown-headed
Covvbird. Colorado Field Ornithologists Journal 30:
67-81.

Cook, T, S.K. Robi.xson, S.I. Roth.stein, S.C;. Sealv, and
J.X.M. Smith. EDITOHS. In press. Ecolog\ and mange-
ment of cowbirds. Lni\ersit\' of Te.xas Press, .\ustin.

Cooke, W'.W. 1897. The birds of Colorado. Bulletin of the
State Agriculture Collection 37 (Technical Series)
2:1-224.

CoRV, C.B. 1912. The niamiiials of IIHuois and Wisconsin.
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(Zoolog}' Series) 153:l-.5()2.

Drew, FM. 1885. On the \ertical range of birds in Colo-
rado. Auk 2:16.

Fk;c;ins, J.D. 19.33. The bison of the western area of the
Mississippi Basin. Proceedings of the Den\er Muse-
um of Natural Historx- 12(4): 16-33.

Friedmann, H. 1929. The cowbirds: a stridy in die l)i()log>
of social parasitism. Charles C. Thomas, Springfield,
IL. 421 pp.

Fhiedma.w, H.. L.F Kiff, and S.I. Rotiistein. 1977. A
further contribution to the knowledge of the host
relations of the parasitic cowbirds. Smithsonian Con-
tributions to Zoologx 2.35:1-75.

Fry.XELL, FM. 1926. A new high altitude limit for the
American bison. Journal of Mammalog\ 7:102-109.

. 1928. The former range of the .\merican bison in

the Rock\' Mountains. Journal of Mammalogv 9:
129-139. '

Fuller, W.A. 1962. The biolog\ and management of the
bison of Wood Buffalo National Park. Wildlife .Man-
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1) 16:1-52.

Gale, D. 1893. Field notebooks, 1883 to 1893. Edited In
J. Henderson (1905j.

Greenwood, RJ., and PH. Harvey. 1982. The natal and
breeding dispersal of birds. .Vnnual Review of Ec()log\
and Sxstematics 13:1-21.

Hank\, L.R. 1985. Recent altitudinal range expansion b\
the Brown-headed Cowtiird in Colorado. Western
Birds 16:18:^184.

Henshaw, H.W. 1875. Report upon the ornithological col-
lections. U.S. Geographical Sunevs \V'est of the
100th Meridian.

Holmes, R.T, and T.W. Sherry. 1992. Site fidelity of migra-
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in J.M. Ilagan HI and D.W. Johnston, editors. Ecol-
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birds. Smithsonian Institution Press. Washington D(;.
609 pp.

Keeler-VVoi.e T., \. ki;i;i,LR-W()i.i; and W.A. (;aeder.
1972. Bird fauna of the vicinit}' of the Rock\ .Moun-
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OrnithologN 15:22-25.

Mayeield, H. 1965. The Brown-headed C^owbird with old
and new hosts. Living Bird 4:1.3-28.

.Meanly, C.A., and D. Van Vlren. 1993. Recent distribu-
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P.vniE. D.L., AND N.A.M. Verreek. 1967. Alpine mam-
mals of the Beartooth Mountains. Northwest Science
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Robinson, S.K., S.I. Rothsteln, M.C. Brittinc;ham, E.J.
Petit, and J.A. Grzybowski. 1995. Ecolog\ and
behavior of cowbirds and their impact on host popu-
lations. Pages 428-460 in TE Martin and D.M. P^nch.
editors. Ecology- and mangenient of Neotropical
migrator)' birds. Oxford Universitx- Press, New ^'ork.
609 pp. '

Roe, eg. 1970. The North American buffalo, 2nd edition.
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Rothstein, S.I. 1975. An experimental and teleonomic
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2.50-271.

. 1990. .\ model s\ stem for coevolution: a\ ian brood

parasitism. Annual Review of Ecologv' and S\stcmat-
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. 1994. The cowbird s invasion of the far west: his-

tor\', cause and consecjucnces experienced by host
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Rothstein, S.I., J. Verner, ,\nd E. Stevens. 1980. Range
expansion and diuiTial changes in dispersion of the
Brown-headed Cowbird in the Sierra Nevada. .Auk
97:25;3-267.

ScLATER, W.L. 1912. A histon of the birds of Colorado.
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Sh.W, J., AND TS. Carter. 1990. Bison uka ements in rela-
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Spencer, R.A. 1985. Brown-headed C-'owbird feeding inci-
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\'an Vlren, D. 1983. Group dynamics and sununer home
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Nan Wren, D., and .M.R Bha\. 1986. Population dynamics
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Warren. E.R. 1906. .Mammals of Colorado. Colorado Col-
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. 1927. Altitude limit of bison. Journal of Mammal-

o,g\ 8:60-61.

Received 23 December 1996
Accepted 27 September 1997

Great Basin Naturalist 58(3), © 1998. pp. 25()-2fi4

CHEMICAL AND BIOLOCICAL CHARACTERISTICS OF

DESERT ROCK POOLS IN INTERMITTENT STREAMS OF

CAPITOL REEF NATIONAL PARK, UTAH

Jill S. Baron', Tobeii LaFrancoi.s-, and Boris C. Kondratietf-

Abstiuct. — Chemical variability and biological communities of rock pools found in small desert drainage basins of
Capitol Reef National Park were characterized over 8 mon in 1994. Neither nooding, dr>ing, nor the presence or
absence of surrounding vegetated wetlands had a great effect on chemical composition, which was veiA' dilute and fluc-
tuated somewhat in response to rain events. Neither flooding noi' dning aftected the composition oi biological commu-
nities in the pools. Summer storms affected onl\ a few drainages at a time, and onl\ a few stud\ pools of signiflcant \()1-
ume dried completeK during the hot, diy summer. This suggests that only a portion of the Wateipocket Fold a(juatic
community is ever distiu-bed at a time, lea\ing undisturbed areas as a source of recovery. Pools bordered by vegetated
wetlands always supported greater nmnbers of species throughout the year than those bordered onh b\' bedrock, but
the same t;ixa were found in both \egetated and Ix'drock pools. The rock pool fauna in Capitol Reef National Park
appear to be resilient to climatic variability.

Kcij words: desert roek pools, mjuatie invertebrates. (Ujuatie eheinistn/. distiirlxmee. Capitol ReefXatioiial Park. I'tali.

Aquatic environments in the arid Colorado
Plateau are extremely important resources for
the maintenance of desert ecosystems. Many
acjuatic resources are ephemeral, characterized
by spatial and temporal discontinuities in flow
(Grimm and Fisher 1992). Ephemeral streams
may flow after storms and snowmelt, but sur-
face water rapidK becomes confined to pools
as the running water evaporates or is tran-
spired (Poffand Ward 1989).

The Waterpocket Fold is a 62 x 1.25-km
(100 X 2-nii) ridge of exposed Navajo sand-
stone that runs the length of Capitol Reef
National Park, Utah (Fig. 1). The Waterpocket
Fold contains many small drainages cut lateralK'
across its width due to water erosion. These
small drainages represent an extreme example
of ephemeral streams. Cut directly into sand-
stone bedrock, these drainages function as
streams only a few days each year. Stream flow
occurs din-ing and inmiediatcK after rain or
snowmelt. Between prccipilalion ex'cnts, water
resides in lock jioojs, many of which are large
enough that ihey rareK diy out. Pools are of 2
nu)r|:)hol()gies: those cut directly into sandstone
\\ ilh no surrounding xcgetalion, and those with
riparian xcgetafion holders. Sand\ aiiuxiaj
deposits thai support xcgelatioii also allow
groundwater storage. Vegetation sni rounding

these pools grades from obligate wetland
species such as Typha latifolia (cattail), Salix
spp. (willows), Phrapnites nu.stralis (reed), and
Carex spp. (sedges) to upland species common
in surrounding desert shrub, pinyon-juniper,
and slickrock communities (Spence and Hen-
derson 1993). Spence and Henderson (1993)
found an increase in the mmiber and abim-
dance of nonnati\e species associated with
pools where cattle grazing had pre\iousl\-
occurred, suggesting that these sxstenis are
\ ulnerable to such disturbance.

Limited information has been collected on
desert rock pools along the Waterpocket Fold
in Capitol Reef National Park. Pre\ ions in\ es-
tigations ha\e addressed (juestions regarding
the role of disturbance b\ flooding on acjuatic
organisms (llaefner and Lindahl 19SS, 1991).
Similar s\ stems of the (Colorado Plateau ha\e
receixt'd more attention, including a chemical
characteri/.ation ot rock pools in northern .Ari-
zona (\'an llaxtMbeke 1990), biologii-al charac-
terizations of tempoiarx pools near \h)ab, L tah
(l^odson 19(S7), and ctosN stem-scale studies in
S\camori' (Ireek, Arizona ((irax and Fisher
1981, Fisher et al. I9S2, Crinnn and Fisher
1992). We c-onducfed a (i-mon intensi\e stud\
to assess the status ol pinsieal and biological
resources as the essential 1st step in managing

'Unilt'd Stales CcoloKical Survt-y. UioIoKical Ri'soiiiccs Division. Naliiral Ki'soiinc I'.
^Department of linldniDlogy, Colorado Slate University. I'ort Collins. (X) S()523.

iii;v l,.il>iM.il.in.(:ulor.ulnSl..lr I

,il\. HmICoIIii

250

1998]

Cai'I roi. Ri:r.|- Hock Pools

251

b. Muley Tanks -^

245a

2240
2380

SCALE
2450 2.5 cm = 0.9 km

'•-■T,,^ ) ^ Halls Creek Narrows

SCALE
2.5 cm = 3.5 km

VvJ.. \. Map slum inn location of Capitul Reef National Park and enlargements of" the 3 studv drainages where hoth
cheniical and biological anahses were conducted: (a) Cottonwood lanks, (b) Mulcv Tanks, and (c) Fountain Tanks. Con-
tour lines on enlargements are in meters.

natural re.sources (Stohlgren et al. 1995). This
stiicK' complemented a larger surxey of 460
rock pools in .SO major drainages (Berghof'f
1994). We explored temporal and spatial vari-
abilitx of pools to answer several questions:
How \arial)le is pool chemistn and ecolog>-

over time and space? Does the presence of
surrounding \egetation inlluence water qual-
it\, pool volume, or ecology? How important
are flooding and drought as disturbances to
both water (jualit\ and aquatic invertebrate
communit>- composition?

252

Great Basin Naturalist

[\blume 58

Site Description

The Waterpocket Fold, also known as Capi-
tol Reef, is a north-sonth trending monocline
of Navajo Sandstone that extends approxi-
mately 112 km north from Lake Powell in
southern Utah (Fig. 1). The Waterpocket Fold
is specifically named for the more than 460
waterpockets, or rock pools, that have been
carved by water and scouring action in the
many small west-east drainages cut into the
sandstone. Drainages are typically <2 km long
and are made up of a series of pools connected
with a drainage depression that conducts water
during and after precipitation events. Because
there is no upwelling of groundwater in the
Navajo Sandstone (Kimball 1988), precipita-
tion is the only source of new water to these
drainages. Rock pools range in volume from a
few liters to >1000 m^. Some vegetated wet-
lands adjacent to pools can have sediment
depths up to 2 m.

Mean annual precipitation ranges from 183
mm at Fruita (Capitol Reef NP headquarters)
in the north to 140 mm near Lake Powell. The
maximum mean July temperature is 33°C,
while the minimum mean Januaiy temperatme
is -8°C (Spence and Henderson 1993, National
Oceanic and Atmospheric Administration 1994).

Methods

Studies were centered on 5 drainages in the
southern part of Capitol Reef National Park:
Cottonwood, Muley, Foimtain, and Miahana
Tanks, and Ciil-Scott (kilch (Fig. 1). Each drain-
age supported pools with and without sur-
rounding vegetation, from which we selected 2
pools with and 2 pools without vegetation for
in-depth study. Those with surrounding xege-
tation were classified as either palustrine
emergent or palustrine scrub-shrub wetlands
(Cowardin et al. 1992). Bedrock-bordered pools
were classified as lacustrine littoral (('owardin
et al. 1992). Drainages ranged Ironi broad and
open at Muley Tanks to long and narrow al
Cottonwood. 1 lie headwaters of ('ottonwood
Tanks originate in a narrow slot canyon. We
made an attempt to select drainages along a
broad length oi the Waterpocket I'bld. 'lb lest
the results of flooding, we chose pools Ironi
among larger, more permanent water bodies so
that they would have water in them when Jul\
and .August storms were exj^ected. In spite of
this seleetiou objectix'c, some pools dried out.

Precipitation and Pool \'olume

We placed rain gages near the top and bot-
tom of each drainage and monitored them
weekly. Each gage was a hmnel that drained to
a coiled tygon tube connected to a plastic liter
bottle. There were slight differences in the
amounts collected by each pair of gages, but
since we were unable to determine whether
differences were due to precipitation variabil-
ity or to gage catch efficiencN', we used the
gage that reported the greatest total precipita-
tion for the sunmier to represent rain for each
drainage. Past experience has suggested it is
veiy difficult to overcollect precipitation in
harsh environments, so the maximum amount
recorded is more likely to represent actual rain-
fall than is a statistical average of 2 gages (Baron
1992). The volume of intensively studied rock
pools was measured weekK' b\ geometrical
approximation using an algebraic fomiula for a
half ellipse, and the depth of water was mea-
sured with a meter tape.

Chemical Analyses

Samples were collected approximately e\'en'
other week from 1 pool with surroimding \ege-
tation and 1 pool without surrounding \'ege-
tated wetlands in Cottonwood, Mulex; and
Fountain Tanks between March and August
1994. We collected 23 samples from Cotton-
wood Tanks (13 from \egetated and 10 from
unxegetated pools), 22 from Mule\ Tanks (11
from each pool type), and 21 from Fountain
Tanks (11 from vegetated and 10 fi-om unxege-
tated pools). Water samples were collected in
125-mL high-density polyethylene (IIDPE)
botdes that had been acid-washcnl in l()9f IICl
solution, rinsed, and stored hill oi deioui/.ed
water prior to sampling foi" pi I and s])eeilie
conductance. Sami)les collected lor major ion
anaKses were stored in 25()-mL IIDPE bottles
that had also been acid-washed with the same
procedures. Because samples eould not be re-
frigerated inunediateK, major ion samples were
preser\c'd with 0.5 niL chloroform (Keene et
al. 1986). Samples were iiltei-ed in the lieKl
with a Nalgene hand pimip through Whatman
(;i'7(' lilteis into baked dark-colored borosili-
eate glass bottles for anah sis of dissoKt'd orgau-
ie larbon. Water temperature was recorded at
the time ol sani|)ling.

Spi'cilic e()ii(lueti\it\ and pi I of water sam-
jiles were deleiinined wcekK using a eondue-
li\it\ (Amber Science Inc. Modi'l (i04) and pi I

19981

Caimtcjl Ulef Kock P(X)l.s

253

meter (Beckinan Model 21). For siimman sta-
tisties pll was eonxcrfi'd to 1 1"*" eoiicentratioiis,
a\era,uecl, and then reeoincrled to pU. Because
pi I \alues eau \ai"\ diiinialK aeeoidiiiii; to alji;al
pliotosx ntlietie aeti\if\ and \\f did not stan-
dai(li/e sample eolleetion times to aeeoiml lor
this, pll \alnes should he \ iewed as approxi-
mate*, rather than absolute. Presened samples
were anaKzed tor major ions within 3—4 mon
after sample collection. Alicjuots were filtered
I Whatman GF/C filters) for cation anaKses.
\hijor ions were anal\ vxxl with ion chroniatog-
1 a[ih\, and alkalinity was anal> zed with a Gran
titration at the USFS Rocky Mountain Forest
and Haniie Experiment Station in Fort Gollins,
Colorado (ODeen et al. 1994). DissoKed organ-
ic carbon (DOC) was analyzed by the USGS
Water Resources Dixision in Boulder, Colorado
(Oceanouraph)' International Model 700 car-
bon auiilxzer). Qualitx' of the chemical analyses
w as assessed by calculating the ion percent dif-
lerence (IPD) between positively and nega-
ti\el\' charged ions. This is an important com-
ponent of being able to inteipret results with
confidence. All but 2 of the samples met 15%
cutoff criteria for acceptable IPD at ionic
strengths of greater than 200 )ieq/L; these 2
(lata samples were discarded (Stensland and
Bowersox 1984, O'Deen et al. 1994). Eight
DOC samples were collected in duplicate;
the\' compared within 10% oxer a range of
3-32 mg C/L.

Comparisons of mean chemical characteris-
tics between the 3 drainages were made using
a Student-Newnian-Keuls test for studentized
range. The studentized range is the difference
between the largest and smallest treatment
means di\ided by an estimate of the standard
error of each single treatment mean. Separa-
tion of the means in the rank order influences
the size of the difference required for signifi-
cance (Ferguson 19S1).

Comparison of the chemisfrx of pools adja-
cent to vegetated wetlands with pools sur-
rounded b\ sandstone was done with a W'il-
co.xon matched pairs signed-rank test. Because
the test assumes independence betxveen the 2
groups being compared, we used a reduced
data set. Connection of the pools during flood-
ing e\ ents invalidates die assumption of inde-
pendence. No \egetated \ersus unvegetated
comparisons were run for Cottonwood drain-
age, since rain events caused obserxed flow

between the Cottonwood pools through July
and August, i^ools in Nhiley drainage were sep-
aiated all summer, as no laiii event was strong
enough to causi' spillage Irom the top pools.
Pools in fountain drainage oxcrflowed only
once, in late July. Chenncal anaKses alter the
Hooding ex'ent in Fountain were excluded liom
the aiuiKsis.

Biological AnaKses

We sampled a(|natic fauna Irom macrozoo-
plankton to \ertebiates wcekK from 4 pools in
each drainage March thiough August 1994.
Additional collections were made in Septem-
ber 1993 and Janiian; Februaiy, and Septem-
ber 1994. Macrofauna were defined as an\' ani-
mals larger than the mesh size (1 nim^) of a
standard dip-net. Based upon previous labora-
t()r\ identifications, we field identified organ-
isms to the lowest practical taxoii, usually
species, and noted dieir life histon stage (juve-
nile or adult). Bottle-trap and light-trap collec-
tions were used for specific identification of
adult insects. A voucher collection of the inver-
tebrate samples has been deposited in the C.P
Gillette Museum of Arthropod Diversity at
Colorado State University.

Semi-cjuantitatixe measures of abundance
were recorded as a rank based upon 3 standard
dip-net sweeps of each pool. The sweeps were
taken from different sides of the pool and the
samples were combined in a single white pan.
Organisms were placed into taxa and ranked 0
(no individuals), 1 (1-10 individuals), 2 (11-50
individuals), or 3 (51+ individuals). Three
additional sweeps were then taken to insure
consistent monitoring of rare species, and an\
taxa found that were not present in the first 3
sweeps were given an abundance rank of 1.
Organisms were returned to the pool after
enumeration and identification.

C^ommon methods for (juantitati\eK sam-
pling the pools were field tested in Februarx'
and March 1994. These were found to be unre-
liable and destructive. In such small systems it
was important to sample nondestructix'eK' to
a\()id affecting pool communities through direct
remoN al of pool organisms. Both a 30-micron
plankton tow and standard Ekman dredge pro-
duced variance as large as population means.
The rock pool organisms do not, however, fit
other characteristics expected of a Poisson dis-
tribution that would exhibit this variance
(Bhattachan^a and Johnson 1977). Rock pool

254

Great Basin Natl iulist

[N'olume 58

coiiinuinitics cannot be assumed to be inde-
pendent of each other, but are affected by tlie
previous community. Standard sampling meth-
ods also were subject to other problems, such as
not accounting lor patchiness of pool organisms
and escape tactics by most adult beetles and
hemipterans. The portable box method (Dod-
son 1987) of (|uantificati()n, which was found
suitable only for shallow pools of <1.2 m, was
inetlcctixe for quantifying the more abundant
benthos such as chironomid larvae.

Cluster analysis and a transformed Pearson
correlation matrix using 22 species were used
to examine the biological stiTicture of rock pool
communities. Species chosen included all
species present on a given sampling day and
represent the major functional groups as well
as the most abundant pool fauna. Pearson cor-
relation coefficients among each species' abun-
dance for a given period were transformed into
a distance measure, and the data were then
treated as distances in a cluster analysis to
determine whether or not groups of organisms
could be considered nonrandomly associated.
Croups of species that appeared together as
clusters between zero and 0.3 were considered
nonrandom associations. This analysis was per-
foiTiied 3 times, using data from the weeks of
15 March, 10 June, and 14 July

The effect of disturbance, defined as flood-
ing, on the number of species present and ratio
of juvenile to adult life histoiy stages was e\ al-
uated with t tests. The effect of pool volume
and temperature on biological parameters was
exann'ned with Pearson correlation coefficients.

Rksults
I ixdrology

rhe suimiiei- of 1994 was uiiiisiially dry,
e\'en for ("apitol lieef National Park. Total pre-
cipitation at (Cottonwood, Muley, and Foimtain
Tanks was 66.1, 27.2, and 31.0 mm, respectively
(Fig. 2). According to the 38-yr record analyzed
by Spence and Henderson (1993), 1/3 of llie
armual precipitation, 46-60 mm, usualK falls
as tliuuderslorms in Jul\ and August (Juhaii
dates 182-243). In 1994 llic juK and August
combined precipitation was 22.7, 5.0, and 31.9
mm at Cottonwood. Muley, and lM)niitaiu Tanks,
respectixcly.

Volumes of the (> intcnsi\(l\ sliidicd pools
with vegetation increased willi laiii cNcnts, al-
though onK 5 CNcnts oxer the cntiic sampling

period caused flooding, defined as overflow
from the pools. Nhiximum measured volumes
ranged from 325 to 800 m-^ for pools bordered
by vegetation and 50 to 635 m'^ for pools bor-
dered b\ bedrock. Minimum \olumes of 0-150
nv^ were measured for pools bordered b\' vege-
tation and 5-150 m^ for pools bordered by
bedrock. Major flash floods did not occur dur-
ing the study period, although flooding was
obsei"ved in Cottonwood and Fountain Tanks,
but not in Muley Tanks. Normalized pool N'ol-
ume values (against maximum measured vol-
ume) with time showed that pool \ohmies
covaried with rain events for pools with and
without sinrounding xegetation (Fig. 2). There
appeared to be less \ariation in volume of
pools with surrounding vegetation and soils,
presumabK' because of the effects of exapo-
transpiration and soil water storage.

Pool water temperatures warmed over the
summer fiom March to mid-April lows (4-18°C)
to highs (32-35°C) in June, July, and August
(Fig. 3). After mid-April most pool waters had
temperatmes in the 22-25°C range, regardless
of location, exposure, or whether the\' were
bordered by vegetated wetlands or bedrock.
Pools were sampled at different times of da>'.
Temperatures indicated in Figure 3 should be
interpreted as within a range of measured tem-
peratmes for any given week because of wide
diurnal \ariability.

Chemical ('haracterization

The waters of the rock pools we sampled
were dilute, with specific conductix ities <200
|LlS/cm and pi I \alues near 7.0. Tlu' ionic ratio
ol calcium to alkalinit\ in the pools was similar
to that measured from groundwater wolls ol
the Navajo Sandstone (calcinm:alkalinit\ of 0.4
in the pools compared with 0.3 reported from
well sami)les b\ Kimball 1988), although the
pools were far more dilute. Ratios of calcium;
silica (>2()) and calcinmisnlfate (>8) did not
compare woll to those in groundwater (calcium:
silica <5, calciuni:sullatc <2). \Miile silica can
be consumed b\ diatoms, it is more likelx that
niineralogical vaiiation in the bedrock and lar
less watei' icsidcncc time in tlic pools iKioinit
lor the diflcrenl chemistries bclwccn ground-
water and surface water.

Phosphate, an essi'utial and oltcn limiting
nntiicnt. was nexcr measured in eonet'utiations
al)o\e detection limits. Nitrate concentrations

1998]

(.Ai'iroi, Hkkk Hock Tools

255

Date

Precip. Vegetated Rock
^ — 2-# — — A —

Fig. 2. Precipitation (bars) and normalized (against maximum measured volume) pool xolnmes (lines) for Cottonwood,
Muley, and Fountain Tanks drainages during the period of study, March-August 1994. Hain events that caused flooding
are marked with an asterisk. Flooding was defined as overflow from one pool to another.

\\(:'re also low, while amnioniiini was present in
soniew hat higher concentrations.

Alkalinit)' and conductivit>' were similar in
concentration to those reported 1)\ Fisher and
(Trinini (19(S3) for an ephemeral desert stream,
and condncti\it> was similar to that reported
1)\ \an Haverbeke (1990) for ephemeral rock
pools. Nitrate was somewhat lower in concen-
tration in the stud>- pools than reported for the
ephemeral stream in Arizona (Fisher and
(irimm 1983). Nitrate concentrations of 4.8-6.5
jiniol/L were much lower than those measured

in summer wet precipitation from the 2 near-
est National Atmospheric Deposition Program
sites, Green River and Bryce Canyon, Utah.
Summer volume-weighted mean nitrate con-
centrations at these 2 sites were 29.1 limol/L
and 43.4 |imol/L, respectivelv (NADP/NTN
1996).

Sulfate concentrations in (Cottonwood and
Muley Tanks (21.9 |amol/L and 27.1 jimol/L,
respecti\el\ ) were similar to sulfate measured
in precipitation (10.7 |lmol/L at Bryce Canyon,
25.1 jLimol/L at Green River). Sulfate was

256

Great Basin Naturalist

[\bluine 5>>

March

April

May

June

July

August

Fig. 3. Pool temperatures (°C) during the stuck period. Circles represent temperatures of pools w ith \egetated w et-
lands; triangles are pools surrounded by bedrock.

higher in Fountain Tanks, with a mean concen-
tration of 38.5 Uniol/L. Fountain Tanks is the
soutliernniost set of" pools for whicli we ana-
lyzed chemical composition and closest to
regional industrial centers that are dominant
sources of sulhn- o.xides in the region (Eatough
et al. 1996). Although it is possible that higher
sulfate values in Fountain Tanks are due to
deposition, and that deposition certainly con-
tributes to the solute load of the pools, it is
more likely that a slight change in bedrock
mineralogy is the source of solutes. The high-
est concentrations of alkalinity, Ca2+, Na+,
Mg-+, and Ch, of all pools sampled were
found in Fountain Tanks, and this suggests the
difference in water (jualit) is due to different
bedrock composition rather than deposition.

Fountain Tanks solutes were 2-3 times more
concentrated than eitlier Cottonwood or Mule\
Tanks (Table 1), except for the major plant
nutrients potassium, nitrate, and i)h()sphate.
The mean pH of Fountain Tanks (7.6) was
slightly higher than the pH of Cottonwood and
xVIuley Tanks (7.0 and 7.3), and llic diflcrciKc
was significant between Cottonwood and Foun-
tain Tanks, but not between I'bnnlain and .\hile\
Tanks iP = 0.01). SiinilarK, cliloride concentra-
tions were slightly liiglii-r lor l-buntain 'lanks,
but signilicantK dilfi-rent onK between I'oun-
tain and Cottonwood Tanks (/' = 0.03). Aniino-
nimn was lower and less variable in l-buntain
Tanks than the other 2 drainages. Concentra-
tions of all solutes in Cottonwood and Mulc\
Tanks were not sigmficantK diifcrent from each

other, w ith the exception of dissolved organic
carbon (DOC). DOC was significantK higher
(10.6 mg C/L), and more variable, in Mule>
Tanks than in either of the other 2 drainages (P
= 0.01). Concentrations of DOC a\ eraged 6 3
and 4.3 for Cottonwood and Fountain Tanks,
respectively.

There was no discernible seasonal pattern
to solute concentrations with time oxer the
summer (Fig. 4). Alkalinitx and calcimn became
more concentrated in \egetated pools of I'bim-
tain Tanks during the summer, but a similar
pattern did not occur in the un\ egetated Foun-
tain Tank pools, nor in pools of either of the
other drainages. Dissohed organic carbon at
Muley Tanks reached concentrations as high as
13.2 mg C/L, possibly because a small rain-
storm flushed organic material into pools from
the surronnding watershed. Anunoniiun and
nitrate coneentiations were liighi\ xariabie
through time, langing from below detection
limits to >(S() \xvi[ NII,/L and 28 |Je(i XO./L.
Then' was no significant difference in concen-
trations within each diainage between pools
sunonndrd by rock oi' xcgeialioii. A plot of
conductance \ersns norniali/ed pool xojume,
using all pools, exhibits a negatixc relationship
(iMg. 5). Drying accounted loi onK ().29'V of
the change in m(>asured conductance lor the
entire data set, but there was \ariabilit\ l)\
drainage. In Fountain Tanks 68*"^ of conduc-
tance variability was explained 1)\ pool dr\ ing,
while 30'^ and 27% were explainable for Mule\
and (Cottonwood 'lanks, respecti\elv

1998J

Capiiol [{eev Kt)CK Pools

257

TaBI.I-: 1. Mean concentrations (and standard dexiations) of inajor ions from 3 drainaijes of Capitol Reef National Park,
L tall. Means with the same letter are not sinnilieantK dillerent. Solutes are reported as [imol/L unless ()then\ise indicated.

('ottonwood T;

inks

Mule\ Tanks

Fountain Tank

s

.\ual\te

Mean (.v)

Sig.

NU'aii (,sl

Sig.

Mean (s)

Sig.

pH

7.0 (0.4)

A

7.3 (0.9)

A

7.6 (0.5)

B/A

Conducti\ it\, fiS/cm

52.5 (34.3)

A

62.1 (41.5)

A

114.8(49.5)

B

Calcium

192.1(157.2)

A

217.1 (152.2)

A

524.0 (279.4)

B

MauncsiuMi

57.6(41.2)

A

65.8 (49.4)

A

135.8 (61.7)

B

Sodium

17.4(13.1)

A

17.4 (17.4)

A

34.8(13.1)

B

Potassium

32.25 (23.0)

A

43.5 (38.4)

A

28.1 (15.3)

A

.■\mmonium

22.2 (33.3)

A

33.3 (44.4)

A

5.5(11.1)

B

Chloride

16.9(11.3)

A

19.7 (22.6)

A

31.0(11.3)

B/A

Nitrate

4.8 (12.9)

A

4.8 (9.7)

A

6.5 (8.1)

A

Sulfate

21.9(13.5)

A

27.1 (3.1)

A

38.5 (15.6)

B

Piiosphate

below
detection

A

below
detection

A

below
detection

A

Alkalinity

502.8 (436.0)

A

555.3 (458.4)

A

1226.8 (729.8)

B

Silica

13.3 (1.7)

A

8.3 (1.7)

A

23.3 (18.3)

B

DOC, mg C/L

6.3 (2.6)

A

10.6 (9.5)

B

4.3(1.7)

A

Biological Characterization

In all pools sampled, 59 separate macroin-
\ertebrate and vertebrate taxa were found
(Table 2). These included fathead minnows
[PiinepJuilcs promelas Ratines(iue) in the lowest
Miahana pool that terminates close to Hall's
Creek, a stream in which this species is com-
mon. Anurans were represented b\ the spade-
foot toad {Scaphiopiis intermontaniis Cope),
canyon treefrog (Hyla arenicolor Cope), and 2
other toads, Bufo woodliomei Girard and Biifo
punctatus Baird and Clirard. The faiiy shrimp
iStreptoccplialus texanus Packard) occurred in
all pools. A snail, PhyseUa sp., was observed in
all drainages. The remainder of the ta.\a were
arthropods, present in both larval and adult
forms.

Larvae of the caddisfly IJinnephilus ialoga
Ross were common throughout the winter and
spring months, and larv al activitv' was observed
even under ice in Januaiy. The mayfly Cal-
lihaetis pictus (Eaton) was found as nymphs
throughout spring, summer, and fall.

Aquatic beetles were well represented in all
pools. The diverse assemblage included preda-
ceous dytiscid diving beetles ranging in size
from the minute Liodessus ajfinus (Sav) to the
larger Dysticiis sp. Common hvdrophilid water
scavenger beetles included Bcrosu^ punctatis-
simus (LeConte) and Tropistemus ellipticiis
LeConte. These water scavenger beetles are

predaceous as larvae but collector-gatherers as
adults (Merritt and Cummins 1996).

Water bugs, Notonectidae and Cori.xidae,
were common throughout the vear. The crawl-
ing water bug family Naucoridae was also found
in late summer. The neuston complex con-
sisted of water striders Aquarius remigis (Say)
and Microcelia torquata Champion, and the
whirligig beetle Gyrimis plicifer LeConte.
Dipterans were represented by a single species
of tabanid. various common chironomids, and
a few mosquito species. Dragonflies and dam-
selflies were common, including Aeshna spp.
and Sympetnan ahtnisum (Hagen) (Table 2).

Most species in the pools are also common
in other a(|uatic habitats of the Colorado Pla-
teau. Small groups of predators dominate the
communities, whose species all appear to be
either extremelv' vagile in dispersal and colo-
nizati(m attributes or adapted to hydrologicallv
fluctuating habitats, such as the anurans (Figs.
6a-c). Associations changed through the sam-
pling period, primarilv' due to life historv phe-
nologies. Sixtv -two percent of species found in
the pools were predators, and each cluster was
primarily composed of species considered pre-
daceous. Thirty-four percent of the species
were herbiv orous collector/gatherers and scrap-
ers, while the remainder were collector/filter
feeders.

The proportion of juveniles in rock pools
decreased throughout spring and summer (Fig.

258

Great Basin Naturalist

[Volume 58

10.0
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Julian day

110 140 170

Julian day

160

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110
' 60

ft

A.

ft

ft

4

«

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^ 150

ft

) 100

A

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35

-

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ft

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ft

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O 21

-

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z 14

-

7

-

0

"

o 1''

A

8

Q 6
1

L_

6

•

10.0

9.0

i. 8.0

7.0

6.0

2000

1600

O 1200

800

400

120

« 80

3100
2500
1900
1300
700
100

« ft

i

fi

ft

8

4

n

n

A

^ ^

.

ft

^

ft

• ft

%

t

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ft

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i

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200
150
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ft

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-ft— '

A A

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ft

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6ft A

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ft-

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?

Fiji. 4. Chcinical tlynainics ol sclcctt-d soliik's ovrr tiiiu' in (a) Cottonwood Tanks, (I)) Miik'\ Tank.s, and (v) Koiintain
Tanks. Solid circles reprt-scnt pools witli sniToiniding vem-tation; opc-ii triangles are I'roni innegetated pools. N'alncs for
calcimn (Ca), siiUatt- (.SO.,), anunoiiinni (.Nil,), nitrate (NO,), and alkalinity (Alk) are in \Xcq/\.. Note dill'erenee in .scale
tor C;a for Fonntain Tanks. Specific condnctance (Cond.) values are in |.lS/cin-, and dissolved organic carbon (DOC) val-
ues are in nig (VI... Jnlian (la\s are iliered daxs of \ear since da\ I on |aiuiai\ 1.

1998]

Caimioi, Hi:i.i" liocK Fools

259

225.0

200.0

175.0

0.0

• •

0.0

• Fountain, rsq=0.68, n=13

■ Muley, rsq=0.30, n=12

A Cottonwood, rsq=0.27, n=13

0.5
Normalized Pool Volume

1.0

Fii^. 5. Hflatioiiship oi specific- coiuliictance l)iS,cm-) with iioniialized pool xoluiiu'. Noiume was nomialized 1)\ divicl
ing weekK \oliinies by the maxiimiin poo! xohinu' nit'asiirt'cl durint; the stud\ period.

7a), liiit there was no difference in the propor-
tion of ju\ enile \ersus aduh stages between
pools with vegetation \ersus those surrounded
1)\ rock (P = 0.586). There were more species
ill pools that were components of vegetated
wetlands (mean = 10.5, .s- = 4.4, n = 116) than
pools situated in bediock only (mean = 7.2,
s = 3.2, u = 116), although numbers of species
declined in both txpes of pools from spring
through summer (Fig. 7b). Neither pool \ol-
ume (P = 0.54) nor temperature (P = 0.74)
affected the number of species present.

The effect of flooding on species numbers
was not significant, either when comparing
numbers of species within all pools before and
after flood events (P = 0.54), or when rock-
liordered pool species numbers were treated
separateK from those surrounded by vegeta-
tion (P = 0.87). Data were normalized 1)\'
square root transformation. To eliminate the
potential for autocorrelation, we did not use
the 2 middle flooding exents in Cottonwood
drainage (see Fig. 2). The first and last storms
were considered sufficientK' separate events to
satisfy' conditions of independence.

A similar test was performed to examine the
responses of pools to dr\ing as a disturbance.
Such disturbances were relati\el\' infrequent

(compared with pools studied b\' Dodson 1987).
Pie-dning numbers of species and ju\enile-
to-adult ratios were tested against post-dning
parameters directly after the first filling e\ cut.
Both \ariables were normalized with square
root transformations. Neither was significantK
different as a result of drying (species num-
bers, P = 0.16; life history stage ratio, P =
0.49).

Discussion

Communities foinul belore and after both
flooding and dning e\ents were \'en similar,
suggesting that hxdrologic extremes do not
constitute much of a stress on communit>' com-
position. Close spatial association of the rock
pools and high numbers of predators in small
systems buffered \ariations in the conmumit>
structure expected to result from plnsical dis-
turbance or competition (McLachlan 1985,
Schneider and Frost 1996). Summer storms
affected onl\' a few drainages at a time, and
only a few study pools of significant volume
dried completeK' during the hot, dr\- summer.
This suggests that onl\' a portion of the Water-
pocket Fold aquatic communit\ is ever dis-
placed at a time, leaving undisturbed areas as a

260

Great Basin Naturalist

[\blunie 58

Table 2. Species list of nuiLioiinerteljralc and verte-
brate rock pool species collected 1 1 September 1993 to 23
September 1994. and 25 October 1995 in Capitol Reef
National Park, Utah.

Vertebrata

CVI'lUNinAK

riiiicpluilcs ])n>im'l(is Rafiiiescjne
Anura

Scaphiopu.s iiitcnnontanus (Cope)
Biifo ptinctatu.s Baird and Girard
Bufu woodhousei Girard
Hijlu arenicolor Cope

G.\STR()I'()I)\

Pliysclld sp.

Nematomorpha

Arthropoda

class Anostraca

Sfirpf(>c('j)h(ihi.s fcxanus Packard
Class Conchostraca

Eulbnnklia texana Packard
Class Nostostraca

Triops h>n<s.icaiicl(iftis (LeConte)
Class .'Vrachnida
Hvdrachnida
Class He.xapoda
Collembola

isolOMlDAE
Ephemeroptera
Baktidak

('(illihuctis pictiis (Eaton)
Odonata
Ae.shnidae

Aeshna multicolor Ilagen
AeslvKi pulmata I iagen
Anax Junius (Drnr\)
LlBELl.lMDAi:

Sympctruin ohtriisum (Hagen)
Lihellula suturata (Uhler)
Lestiijae

Archilestes grandis (Rambnr)
Coenacrionidae

Enallagiua cijalhigcruin ((iliariK-ntier)
Ar^irt sp.
Hemipteia

NoTONECTIDAK

Noloni'cta kirhiji linnm-rlord

Notonccta undidata Sa\

Buenoa nuirgdriliiccd Toric-BMcno
Nalcohidae

Ambrysus inonnon inonnoii Montandon
G ERR I DAK

Aiiudiius r('mi<iis (Say)

\ Kl.llDAH

Micnnclia lonpidtd Clumipion

CORIXIDAE

Graptocorixa ahdoiniiidlis (Say)

liEl.OSIOM.VnDAE

LctluHCVUs aiiiihcdiius (Leidy)
Trichoptera

l,i\!Ni:i'iiii.ii)\i:

IJnuicpliilus Idlogd Ross
Coieoptera

(iVHINinAE

Cyrinus plicifer LeConte

HVOROPHIEIDAE

Hydrophilus thdiiguldris Say

Tropistcrnu.s cllipticus (LeConte)

Hydrochard lincdtd ( LeConte)

Berosus piincidtissimus LeConte

Laccohius sp.
Dytiscidae

Agdhus disintcgrafus (Crotch)

Agdhus lugens LeConte

Agabiis fristis Aube

Agabus semivittatus LeConte

Rluintus gutticollis (Sa\)

Laccophilus uuiculosus decipicns LeConte

Stictotarsus stridtcllus (LeConte)

Liodessus affinus (Sa\)

Neoclypcodyti's discretu^s (Sharp)

Hygrotus colhitus (Fall)

Thennoiu'ctus iiidnitordtus mdniiordlus
(Hope)

Uvarus subtdis (LeConte)

Dytiscus sp.
Hampi.idae

Pcltodytcs callosuN (LeConte)
Diptera
Taranioae

Tdbanus sp.
Chironomume

Chirouomus sp.

Polypcdduin sp.

Pluwnopscctra dyah (Tow nes)

Pluicnop.scctra sp.

Micropsectra sp.

Alotduypus sp.
Cer.\T()P()(;()nidae

Bezzid s|i.

CULICIOAI

Anopheles Irdiisiseaiius \lc(.'rackcn
C.'///('.v tdisdlis Co(|uillctt
Culisctd iiionidtd (\\ illislon)
('ulisetd sp.

.source ol iccoxciy. .Main ol the s|H'ci(,'S we c'oinpoiu'iil.s ol \ ftictati'd wt'tlaiids siiiiportcd

foiiiid were well adapted lor rapid rocoloiii/a- u;rt'at('r iiuiiihors ol .spocics throuiiiioiit tlu-

tioii ol pools alter disliiihaiiee, lia\iii.i:; liiiilily \ear, hiit none ol these species oceuncHl onl\

niohile adult statues, terrestrial adult uiatiuti; in jiools with vegetated wetlands. The lack ol

and dispersal slaj^es, or aiu'nial- or wind-dis- distinct species associations in tlu' cluster anal\-

persed e^^s. Hecolonization can also come sis implies that all species occupied a similar

from survivors or c^^s laid prior to (listurl)ancc ccolouical niche, which is likcK the rivsult ol

(Crushing and Ciaines 1989}. Fools that were close ecological association, and pro.\imit\ and

1998]

Capiioi, |{ki:k Hock Pools

261

3, PS Scaphiopus intermontanus ■

C,S Bufo spp

P.S Chironomidae

P Rhantus gutticoliis

C Laccophilus maculosus d ■
P Stictotarsus stnatellus —

P bodessus affinus

P Aguanus remigis

S bmniphilus taloga

P Ceralopogonidae

F Culiadae ^~^^l^^^^

P Agabus spp

S,C Hyla arenicolgr_

S Physetia spp

P Notonecta kirbyi

P Graptoconxa abdominalis

C Callibaetis picta

P Gynnus plicifec

C Hydrachnida

P Ubeltula saturata

C Tropisternus ellipticus
C Beivsus punctatissimus

c.

P Pimephelas promelas
C,S Hyla arenicolor —

S Physella spp

C Callibaetis picta

P Aeshna/Anax spp

P Ubellula saturata

P Arctiilestes grandis
P Microvelia torquata
P Graptoconxa abdominalis
C Hydrachnida

P Notonecta kirbyi

P Aquanus remigis

P Ceratopogonidae

C Tropisternus ellipticus

C Laccophilus maculosus d
F Culiadae

P Gynnus plicifer

P,S Scaphiopus intermontanus -
C.S Bufo spp

F Streptocephalus texanus

F Eulimnida texana

P Tabanus spp

P.C Chironomidae

C Berosus punctatissimus

P Rhantus gutticoliis

C Hydrophilus tnangulans

P Uodessus affinus

P Dytiscus spp

P Thermonectus marmoratus m

P Stictotarsus stnatellus

04

SC Bufo spp.

S,C Hyla arenicolor

C Nematomorpha

P Graptoconxa atxiominalis .

C Berosus punctatissimus

S Physella spp

P Aquanus remigis

C Callibaetis picta

C,P Chironomidae

P Ceratopogonidae

P Ubellula saturata .

P Gynnus pliafer

P Aeshna/Anax spp

C Tropisternus ellipticus .

P Notonecta kirbyi

F Culiadae

P Stictotarsus stnatellus

P Ijodessus affinus

P Rhantus gutticoliis

C Laccophilus maculosus d .

Fig. 6. A\ erage linkage cluster anaKsis for aquatic species collected on (a) 15 Marcli 1994, (h) 10 June 1994. and (c) 29
JuK- 1994. Clusters are e.xpressed as normalized root mean sfjuare distances. Species are annotated with functional feed-
ing group after Merritt and Cummins 1996 as follows: P, predator; S, scraper; C, collector/gatherer; and F, filter feeder.

262

Greai I5asi\ Natur.\list

[\blunie 58

J I I 1 I L.

March April May June

August

Fig. 7. Characteristics of'aciuatic organisms in Capitol Reef rock pools over time: (a) average ratio ot ju\enile to adult
stages, and (h) species numbers. Circles are numbers in pools with \egetation, and triangles are numbers in pools sur-
rounded b\' bedrock.

similarity of the rock pools. The altenuiti\e,
which was not observed, would have shonn
persistent and distinct clusters of species.

The rapidity of recovery suggests these sys-
tems displa\' great resilience, a conclusion also
reached in a studx ot macroinxertehrate recov-
ery after flash floods in Sycamore Creek, Ari-
zona (Grimm and Fisher 1989). Flood events
can introduce nutrients and detritus from pre-
cipitation and upstream as they wash debris
and salts from upstream contributing areas
(Creed c-t a!. 1996). Grimm and Fisher (1989)
hypothesize flood events are necessar\ to tlic
maintenance of macroinvertebrate populations
because they refresh the lood supply lor last-
growing organisms.

Inhere was a chciiiital icspoiisc to drying and
Hooding in the pools, althongh the strength ol
the response xaricd 1)\ solute and pool. It
appears that nntiicnts and !)()(; increased alter
flood events, bnt salts became more concen-
trated with drying. Some chemical constitn-
ents, such as alkalinitx, increased 1)\ an oidc r
of magnitude during the stucK' period (concnr-
rent with declining pool volume) l)\it rapidK
decreased after a rain event (Fng. 4). Pool chem-
istry was veiy dilute and was not signilicantK

influenced b\' the presence or absence of \ege-
tated wetlands.

In summar\-, rock pools ol Capitol Heel
National Park are populated with a launa well
adapted to sm"\i\al in an en\ ironment ol In dro-
logic extremes. The dilute chemical concentra-
tions we measured did not vaiy broadly enough
to pose a salinit\- problem for aquatic organ-
isms. The abilitx of conununities to recoxer
after floods and droughts is consistent witli a
hypothesis posed b\ I hues (1970) and results
found by others (summarized by Gushing and
Gaines 1989), that streams with llasln Indrol-
()g\ should \vd\v less abundant and less \aried
fauna than others. C-ushing and (»aines (1989)
developed a elassiflcation scheme lor coloniza-
tion and recolonization eliaracteristics ol difler-
ent stream t\pes. Capitol \\vr\ rock pools lit well
under the elassilication lor exoiheie cold desert
streams in that the nian\ small sircanis ol the
W'ateipocket I'bld pro\ ide colonization sonrees
lor each other 'fhe dixersity ol stream and
drainage habitats oilers man\ pathwa\s lor lau-
nal icc'oxcrv inclnding downstream drilt, up-
streani niigialion. both snrlacc and Inporheic
refngia in wetlands snnonnding some pools, as
well as adnlt and egg snr\ ivors ol disturbances.

1998]

Capitol Hkkk Hock Pools

263

Ac:kNO\\LEUt;MENTS

Thanks to Xorni Ilcndeison, SancK Bortli-
w ick, Ke\in Bt'iulioll, and Joel Waiincr ol tlic
National Park Sen ice for proxiding logistical
and financial support for this research. Eric
Allstott. Brian Xewkirk, and Louise O'Deen
assisted with the data anahsis. Sand)' Borth-
\\ ick, Joel Wagner, and an anonymous re\ie\\er
provided \aluable re\ie\vs. We thank the
National Park SeiAice, Natural Resource Infor-
mation Di\ision, for the state and park insert
on Figure 1. This project was hmded 1)\ the
National Park Senice, C:ontract #CA 1268-2-
9004.

LnilKATLHK C'riKD

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tem— Loch N'alc W'ateislicd. S|)rin,2ier-Vei"lag, New
York.

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sur\e\- suminan report. Resomce .Vlaiiagenient Di\ i-
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CowARDix, L.NL, V. Caktck, EC. CioiKi, \\n E.T. LaHok.
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Wildlife Ser\icc F\VS/OBS-79/31. 131 pp.

Cref-D, I.E, L.E. Ba\I5, N.W. Eo.stfr, LK. .Morrkson, J.A.
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CrsHlXG, C.E., AXD W.L. Gaixes. 1989. Thoughts on re-
colonization of endorheic cold desert spring-streams.
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DoDSOX, S.I. 1987. Animal assemblages in temporar> desert
rock pools: aspects of the ecology- of Dafn/helea suh-
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Eatolgh, D.J., M. EvroiciH, axd N.L. E.vtough. 1996.
Apportionment of sulfur o.xides at Can\onlands din-
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SO^ to sulfate in the Green Ri\er Basin, .\tmosplieric
En\nronment 30:29.5-308.

Ferglsox, G.A. 1981. Statistical aiiaKsis in psychology
and education. 5th edition. McClraw -Hill Book Co.
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Fisher. S.G., L.J. Gr.\y, N.B. Grimm, and D.E. Bisii. 1982.
Temporal succession in a desert stream ecosystem
following flash flooding. Ecological Monographs .52:
9.3-110.

Fisher, S.G., axd N.B. Grimm. 1983. Ihdrologic and
material budgets for a small Sonoran Desert water-
shed during three consecuti\e cloudburst floods.
Journal of .\rid En\ironments 9:10.5-118.

Gr.\y, L.J., AXD S.G. Fisher. 1981. Post-flood recoloniza-
tion pathways of macroin\ertebrates in a lowland

Sonoran Desert stream. Svcaniore (^leck. .\ri/.()ua.
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Gni\i\i, N.J., AXD S.C;. Fisher. 1989. Stabilit\ of peripln-
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can iii'nthological Societ\ 8:293-307.

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climate. Pages 211-233 in P. Firth and S.G. Fisher,
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C;reat Basin Naturalist 58(3), © 199S, pp. 265-272

SURVnOHSllIPAXDCAl SI' -SPI'CIFIC MORTALITY
IN I'IM<: POPL LVnONS OV MULE DEER

Vernon C. Bleich'- and 'Innofln |. Taxlor'^

ABSTRAcn". — We used retrospeetiv e auaK ses to in\ estiuate cause-speeifit mortality and sur\i\()rsliip anions 5 popula-
tions of nuile deer (.V = \6H telemetered animals) wintering in the \\-estern (weat Basin during 19Sf>-1994. Tliese i^ojiu-
l.itions existed under similar environmental eonditions. hut sunivorship funetions differed among them. MoiitliK sur-
\ i\al ranged from ().9(i4 to 0.990, and annual suni\al ranged from 0.643 to ().S84. ihe proportion of deaths attributed to
predation and malnutrition or anthropogenie causes did not differ among the 5 pcjpulations. Predation was the leading
cause of mortalit): mountain lions were responsible for appro.ximateh- 90% of the deer killed by predators. No difference
existed among these populations in the proportion of telemetered deer that were killed by mountain lion.s, but propor-
tionalK more females than males were killed In these large felids. Predation liy mountain lions is the pn'man' source of
mortalit)' and a widespread phenoinennu among the populations of nuile deer we investigated.

Key words: Calijoniia. Felis concolor, Odocoileus hemionvis, uitilc deer, inoiiality, inouiitdiit lion, pndalkm. survivorship.

Populations ol mule ck'ff iOdocoih'Us hcin-
ioniis) lui\e been declining in western North
.\nieriea for nian\ \'ears (Wbrknian and Low
1976), and effects of nutrients, competition,
liredation, and climate on these populations
have been debated among numerous investi-
gators. Mule deer are thought to be densit\-
dependent in their response to resource a\ail-
ability (McCullough 1990). In unpredictable
emironments (typical of much of the Great
Basin), however, it may be difficult to base
management recommendations on density-
dependent responses anticipated to follow pop-
ulation declines (Mackie et al. 1990). What-
e\ er factors. singularK or in combination, reg-
ulate mule deer populations remain open to
discussion. Indeed, there is general agreement
that no single cause can be invoked. Detailed
and specific investigations are necessary to
exaluate factors that ma\' regulate populations
of these important game animals (Hornocker
197fi Knowlton 1976, Connolly 1981).

Recenth', Wertz (1996) expressed concern
about the dynamics of several nuile deer pop-
ulations wintering in the western Great Basin.
llighwa\ mortalit) has been a basis for this
concern, as have the effects of predation and
disease. Persistent drought has lowered the
carrying capacity- of deer winter ranges in this
general area, with resultant negative influences

on the plnsical condition of these large lierbi-
\ores (Kucera 1988, Ta\lor 1996). Moreover,
the harsh winter of 1992-93 killed man\ deer,
particularK' in northeastern California and
northwestern Nevada (Wertz 1996).

To better understand factors affecting deer
populations in the western Great Basin, we in-
xestigated seasonal distribution, habitat selec-
tion, cause- specific mortality, and survivorship
in 5 populations of mule deer wintering in
eastern California and western Nevada. In this
paper we use retrospective anaKses based on
telemetered animals (White and Carrot 1990)
to compare cause-specific mortality among 5
mule deer populations that winter in the west-
em Great Basin. AdditionalK, we describe and
compare survivorship functions for female
deer in these populations.

Descriftkjn of the Study Area

Our study area is located in Mono and Inyo
counties, California, and Douglas County,
Nevada (Fig. I). Deer from the West Walker,
East Walker, Mono Lake, and Casa Diablo win-
ter ranges are migrator)' and displa\' annual
patterns of movement and range use. In spring
they make long-distance moxements, some-
times >6() km, and spend sunuuers on both
the east and west slopes of the Sierra Nevada

'California Department of Fish and Game, 407 W. Line St., Bishop, C.\ 9.3.514.

-Institute of Arctic Biolog\ and Department of Biologx and Wildlife, Unix<Tsit\ of .\laska Fairbanks, Fairbanks, AK 99775.

3Box 191. June Lake, CA 93529.

265

266

Great Basin Natl iulist

f\()lume 58

^1^^^ WEST WALKER

N

CA ^

^^^^P EAST WALKER

/

. ^. NV

•J?\ MONO LAKE^M \
^ CASA ^^^^ ^

'^ DIABLO ^^H^^
^ ^^^^P \ 1 50 KM

1

1

"^ ■ BISHOP \

118° 30' W INYO ^^B \

37° N

1 MOUNTAINS \

\

1 \

Fig. 1. Location ot 5 winter ranges in northeastern California and western Nevada. .Mule deer concentrate on tliese
areas from appro.xiniateK 1 No\emher to 15 Ma\' each year.

(Taylor 1988, 1991). During autumn deer from
these populations return to discrete winter
ranges on the western edge of the Great Basin,
where they remain from about 1 November to
15 May (Taylor 1988, 1991). Deer inhabiting
the Inyo Mountains undergo altitudinal
migrations similar to those described b\'
Nicholson et al. (1997), but generally do not
exhibit the extensive movements made by deer
from the other 4 populations. Currently, 4 of
the populations (West Walker, East Walker,
Mono Lake, Casa Diablo) are classified as
Rocky Mountain mule deer (O. h. hemionus);
deer occupying the Inyo Mountains are classi-
fied as Inyo mule deer (O. h. inyocnsis), a ta.\on
of (juestionable \alidity (Wallmo 1981, Cronin
and Blcich 1995).

During winter all 5 populations of deer
occur largely in sagebrush {Artonisia tridcn-
tata) steppe or pinxon pine (Piniis )no)io])h\iU(i)
habitat, ranging in eIe\ation from 1500 ni lo
2300 m (Taylor 1988, 1991, V.C. Blcich and D.
Racine unpui)Iished data). 'Ihc priiiiar\ \\ inter
forage for the 4 northern populations is bittei-
brush (Piirshia spp.; Taylor 1988, 1991).
Although bitterbrush occurs in the Inyo Moun-
tains (DcDeckcr 1991), specific data on dcci
diets in that range are lacking.

The Sierra Nevada creates a lormidablc
rain shadow, and during winter these dei-r

occupy an arid region with low and vmpre-
dictable precipitation (Fig. 2), similar to that
described 1)\- Kucera (1988). Since 1986, the
Great Basin immediatcK east of the Sierra
Nevada has experienced repeated annual
droughts; as a result, ecological carrxing
capacit\' of many winter ranges has declined
(Ta\lor 1991). Migratorx populations of nuile
deer can be substantialK affected b\ drought
conditions on winter ranges despite adeciuate
forage during sunnner (Kucera 1988V Dming
years of low precipitation, bitti'rbrush produc-
tion is poor and deer subsist on suboptimal
diets consisting largeK' of conifers, sagebrush,
and blackbrush (C()lc()<iync raiiiosissitna; kucera
1988, Ta> lor 1991).

M

i; I lions

During 1986-1991. wc- nsi'd Clowr (1956)
trajis, a helicopter and linear drixc ni'ts
(Thomas and \o\ak 1991), and a hand-held
net gun fired Ironi a liclic()|iti'r (Krausnian ct
al. 1985) to capture mule dec-i-. We fitted adult
(>l-yr-old) animals with color-codi-d eai tags
and l('lemetr\' collars (Model 500. lelonics.
Inc., Mesa, AZ) that ini-orporated a niortalitx
sensor with a 6-h dela\. We collared t'aeli ani-
mal at its capture site and ri'leased it wlu'n
processing was completed. B\ distributing our

1998]

Si u\i\()Ksiiii' wi) MoiiTAi.rrv oi- Mi i.i; Dkkk

267

0 10 20

TEMPERATURE (C)

Fig. 2. Climate throughout the study area t>picall\ is
cold during winter and hot during sinnmer. Precipitation
occurs priniariK as snow fall during w inter, hut \ ariance in
annual precipitation is high. The climograph was de\el-
oped from data obtained 1961-1990 from the Western
Regional ('liniate Center using the mean of monthK mean
\alues of minimum and maximum temperatures for
Bishop, Bridgeport, Bodie, and Independence, Calilbniia.

capture efforts throiigliout all winter ranges,
\\ f minimized potential biases associated with
lieterotieneous use of those areas by deer We
collait'd male and female deer in the appro.xi-
niate proportion of their occurrence in each
population. Each winter, we used ground-
based chemical immobilization or a helicopter
and net gun to capture and radio-collar addi-
tional deer in each population.

In the 4 northern populations, we used aer-
ial and ground telemetn to monitor the status
ot deer at intenals <1 wk; thus, date of death
could be closeK estimated. Using only aerial
telemetr\ in the In\ o Mountains, we monitored
those deer at appro.\imatel\" 2-wk intervals.
for animals for which we could not ascertain
tlie date of death, we assumed death occurred
midway between the last known live obsena-
tion and the date on which a mortalit\' signal
\\ as first receixed.

We attempted to determine the cause of
mortalit) for e\ en deer that died. For animals
killed by predators, we used the criteria of
Shaw (1983) and Woolsey (1985) to identif\-
the species of predator in all but one instance.
Nutritional status was indexed b\ condition of
marrow in long bones (Cheatum 1949). W'hen

we could not ascertain the source of mortality,
we listed the cause of death as undetermined.
G-tests were used for categorical analyses, and
a binomial test compared the proportion of
deer killed b\ mountain lions dming difli rent
years (Zar 1984).

We used the Kaplan-Mt'icr (1958) estima-
tor, as modified l)\ Pollock et al. (1989), for
staggered entr\ of telemetered females into
each population, and determined siu'xixorship
on a monthK basis. To compare survivorship
functions, we used the log-rank test (Cox and
Oakes 1984) as modified by Pollock et al.
(1989). We calculated the most coiiscr\ati\ e
chi-S(|uare statistic presented I)\ Pollock et al.
(1989) to enhance the probability that an\ dif-
ferences detected between surxixoiship func-
tions were real.

Sunixorship was not evaluated on all win-
ter ranges concun"ently, and deer were not ini-
tially collared at the same time of year. To min-
imize seasonal effects on mortalitx* in this ret-
rospectixe analxsis, xxe compared surxixorship
of females from paired populations from the
beginning of the 1st April during which col-
lared deer from each population pair were
a\ ailable to the end of the period for xxhich
paired monthlx data were available tor those
particular populations. For example, xve studied
cause-specific mortalitx' in the West Walker
population during April 1992-January 1995,
and in the Inyo Mountains population during
October 1991-December 1994; for this pair,
comparisons of surxixorship cun'es spanned a
period of 2 xr and 9 mon, from 1 April in xear
1 to 31 December in xear 3. Using this method,
xve compared survivorship over periods of 21
mon for 4 pairs of populations, and oxer 27
mon for 5 other pairs. To facilitate comparisons,
xve also calculated finite, annual, and monthlx
survivorship for females in each population.
We restricted our analyses to females because
the genders of sexuallx dimorphic imgulates
max' occupy different habitats, experience dif-
ferent risks of natmal mortality (Bleich et al.
1997), and respond differentlx' to the threat of
predation (Bleich in press).

We collected data for a minimimi of 24 mon
in the Casa Diablo population and a maximum
of 39 mon in the Inyo Mountains. Although
the inxestigations did not all nm concurrently,
these 5 populations occupy similar habitats in
close proximity to each other, they were
exposed to similar climatic regimes (Table 1),

268

Ghkat Basin Naturalist

[Volume 58

Table 1. Correlation matrices for diinatological data obtained 1961-1990 from the Western Regional Climate Center
for Bishop. Bridgeport, Bodie, and IndepeiidenLe, Caliibrnia. These stations are all located on or near the winter ranges
investigated herein.

.\\erage monthly ma.\innun tcinpcrature

Bishoj)

Bodie

Bridgeport

Independence

Bishoi)
Bodie
Bridgeport
Independence

Bishop
Bodie
Bridgeport
Independence

l.OOO
0.996
0.996
0.999

1.000

0.9SS
1.000
0.997
0.997

0.995
0.995
1.000

0.995

0.936
1.000

0.972
0.934
1.000

l.OOO
0.9S7
0.995
l.OOO

Bisliop

Bodie Bridgeport

Independence

A\'erage montliK mininunn tcmperatnre

.\\erage monttiK precipitation

Bishop

Bodii- Bridgeport

Independence

0.996
0.935
0.979
1.000

and several of the investigations were ongoing
simultaneously. Thus, we assumed that quali-
tative differences among these winter ranges
were minimal.

Results

We radio-collared 168 adult mule deer (27
males, 141 females) and monitored them for
21-39 mon (2829 telemetry-months; Table 2).
We determined the proximate source of mor-
tality for 76% of the females (41 of 54) and
85% of males (11 of 13) that died. Among
females, confirmed causes of death ranged
from 57% in the Inyo Mountains to 100% in
the East Walker population. Among the 41 mor-
talities of females for which the cause of death
is known, 83% were attributed to predalion,
4.8% were human-induced, and \2..1'y< were
due to malnutrition. In the northermiiost pojv
ulation (West Walker), 3 ol 10 mortalities result-
ing horn predation occurred chiring or iminedi-
atcK alter the severe winter ol 1992-93, and
7 of 10 occurred during or lollowing the
mild winter of 1993-94 (V > 0.10). Among
males that died, predation 1)\ mountain lions
accounted lor .36% and liiinling lor 64% ol the
11 mortalities lor which the cause of death
was determined; the source ol iiiortaiitN loi- 2
males could not be ascertained. \\c detected

no evidence of malnutrition among animals
killed by predators or among those d\ing of
anthropogenic causes.

Predation accounted foi- >7()% of the kiiowii
causes of death for females on each winter
range (Fig. 3). The proportion of deaths attrib-
uted to predation did not diller among tiiese
populations (G = 5.987, df = 4, /' = 0.200)
when human-induced mortalit) and malnutri-
tion were pooled. For males, sample sizes
were too small to allow a comparison among
populations.

Of 34 female mule deei' killed b\ [in'ilators,
mountain lions accomited for 91% of the
deaths (Fig. 4). No difference existed among
the 5 populations in the proportion ol lemales
killed by mountain lions (C = 2.979. dl = 4, /'
= 0.561). ()\erall, the proportion ol lemale
deer whose deaths were attributable to preda-
tion b\' mountain lions (31 of 41) was signili-
canth greater than the proportion ol males
killed In these large lelids (4 of 1 1; G = 5.751,
(|(= 1,/^ = o.OKij.

Smvi\()rship hmctions ol lemale deer dil-
lered significantK for 3 of 10 paii-w isc compar-
isons (Table .i). ,Snr\ ixorship lor the West
Walker population dilfered Ironi the Mono
Lake, in\() Mountains, and Fast W'alki'r popu-
lations, and was marginalK nonsignificant for
the (lasa Diablo population. The finite sunixal

1998]

Si lu ixoKsiiii' \\i) Moin \i.i 11 ()i Ml i.i. Di;i:i{

269

Table 2. Sample sizes and estimates ol monthly and annual sm\i\()islii[) for West Walker (W\V), Casa Diablo (CD),
East Walker (KNN). Mono Lake (Ml.), and ln\o Mountains (IM) mule deer iiojiulations, Inyo and Mono eounties, Cali-
lornia. and Douglas C>ounty, Ne\ada, 198(^-1994.

Winter

Deer

Telemet

n-

MonlhU

.\nnual

range'

i.Vi

months

(.Vi

sur\i\()rshiii

•''v

suiAixorship

■'<x

WW

4S

823

0.964

().()()4

0.643

0.010

CI)

27

469

0.985

().()()4

0.837

0.014

i:w

23

428

0.990

().()()4

0.884

0.014

\ii.

2.3

512

0.979

().()()6

0.777

0.018

IM

20

.597

0.973

O.OO-S

0.717

0.022

'luclusiM-clak-s of filch investigation wert- W\\. April lyy2-Jami.(n 199.5: CD, J.iiiuan 19S()-I)(iiiiil)< r 19S7. I'.W. M.ircli 19.SS-Juik- 1990, Ml.. XLiixli 1988-
Imu- 1990; IM. 0(toI)er 1991-Dec-enil)er 1994.

rati' aiiioiiu tlie.sc population.s ranged from
about 0.73 in tlie East Walker population to
ahout 0.30 in the West Walker population,
which had the hiiihest proportion of niortalit\
caused by malnutrition. Among these popula-
tions monthK suni\al estimates ranged from
0.964 to 0.990, and annual survival estimates
ranged from 0.643 to 0.8S4 (Table 2). Too few
males were marked to allow a meaningfvd esti-
mate of sur\ i\()rsliip for males occurring in
these populations.

Discussion

Predation was the most common cause of
mortality among 5 mule deer populations that
winter east of the Sierra Xe\ada (Fig. 3).
Human-induced mortalit\' and malnutrition
\ aried among these populations. Based on our
analyses, we conclude that sources of mortal-
it\ were similar among these winter ranges for
the periods we studied. Deaths of female deer
resulting from himian activities were recorded
onl\ in the West Walker and Casa Diablo pop-
ulations. Death resulting from malnutrition
was restricted to the West Walker and \h)no
Lake populations and accovmted tor 25% and
21% of the mortality in those populations,
respectively. Malnutrition overall (9.8%) was,
however, not an important cause of death.

Among deer killed b\' carnivores, mountain
lions were the most conniion predator, and no
differences existed in the proportion of female
deer killed by mountain lions among the 5
populations we investigated (Fig. 4). Our find-
ings are consistent with previous ones that
mule deer are important prey of mountain
lions throughout western North America
(Homocker 1976, Russell 1978). ProportionalK"
more telemetered females than males were
killed, suggesting that females may be more
\ ulnerable to predation b\- mountain lions.

There was a difference in sur\ ixorship func-
tions between 3 of 10 pairs of populations that
we conipared (Table 3). and the results were
but marginalK nonsignificant for a 4th pair.
Small samples possibK^ influenced our ability
to detect differences (Pollock et al. 1989) be-
tween other population pairs, but the magni-
tude of differences between 6 pairs, when
compared to the remaining 4, suggests sample
size was not problematic (Table 3). These find-
ings were somewhat unexpected given the
physical, climatological, vegetational, and fau-
nal similarities among the winter ranges we
examined, and ma)' be attributable to the high
proportion of mortality from malnutrition in
the West Wilker population during the winter
of 1992-93; that winter was especialK' severe
in northeastern California (Wertz 1996).

In none of our study populations are histor-
ical demography and habitat quality adequately
known to begin to factor out the relative roles
of mitrition, predation, and climate as factors
influencing the dynamics of these populations.
Additionally, the effects of these factors on
sur\ i\ al of young < 1 yr old were not investi-
gated. With the exception of the .Mono Lake
and West Walker populations, the absence of
animals dying of malnutrition suggests that
mortalit) from predation generally was not
compensator). \hmy female deer collected
from the West Walker winter range were in
poor physical condition following the winter
of 1992-93 (Taylor 1996), and some animals in
that population ma\ ha\ e been predisposed to
death b\ predation during our in\estigation.
Nevertheless, only 3 of 10 animals killed by
predators in the West Walker population died
that winter, but 7 of 10 were killed during the
mild winter of 1993-94. Despite the deaths of
2 females from malnutrition in the Mono Lake
population, individuals there were in much
better condition than were West Walker females

270

Cheat Basin Natuiulist

[Volume 58

14

□ PREDATION
□ANTHROPOGENIC

□ MALNUTRITION

CD ML EW WW IM

DEER POPULATION

10

□ MOUNTAIN LION

□ OTHER PREDATOR

CD ML EW WW IM

DEER POPULATION

Fig. 3. Proportion oi niortalitit'S (A' = 41) of female deer
that can he attril^uted to predation, anthropogenic canses,
and niahiutrition in each of 5 deer popidations inhahiting
eastern California and western Ne\ada, 1986-1994. Num-
bers above eacli l>ar are total mortalities from known
causes for each population; CD = Casa Diablo, EW —
East Walker, ML = Mono Lake, WW = West Walker, and
I\l = IiiNO Mountains.

Fig. 4. Proportion of jiredation on female deer attril)-
uted to moimtain lions and other predators in each of .5
deer populations studied in eastern (California and west-
ern Nevada. 1986-1994. Numbers abo\e each bar repre-
sent total mortalit\ attributed to predators for each popu-
lation; CD = Casa Diablo, EW = East Walker, M L =
Mono Lake, WW = \\'est Walker, and IM = bno .Moun-
tains.

(lurint^ 1992-93 (Taylor 1991). Body condition
of Mono Lake females durini^ the period they
were under stud\' approached that of the West
Walker population during 1994, a year when
no animals died of malnutrition. None of the
animals killed by predators exhibited evidence
of depleted fat reserves upon examination of
femur marrow. If malnutrition was an impor-
tant factor predisposing indi\'iduals to death
by other causes, we would have expected to
find evidence of such among victims of preda-
tion or human-induced inortalitx'; this was not
the case.

The role ol predation in ifgulatiug popula-
tions of large manunals remains open to
debate (Skogland 1991), and predation as a
factor potentially regulating deer populations
has not been widely accepted (C'onnolly 19cSl).
For example, the effects of mountain lion pre-
dation have been described as unimporlaul
(Janz and Hatter 1986) and con\'ersel\ as ha\-
ing strong local effects (McNay and Voller 1995)
on deer occurring in the same geographic
area. These large lelids were responsible lor
most mortality of adult female deer in each of
tiie populations we inxcstigated. Although we
noted few adults killed by lONotes {('(iiiis
latran.s), tlu'se canids can haxc important
effects on deer population dyuainics, es|)e-
cially through their inlluence on lawu siu\i\al
(^Knowlton 197fi, Bowver 1987).

Predation ma\- warrant special considera-
tion as a factor in the d\ luunics of nmle deer
occup\'ing unpredictable en\ ironments. Indeed,
investigations in boreal systems have sug-
gested that predation by wolves {Canis lupus)
and bears {Ursus spp.) can preclude recoven
of large mammal populations that ha\e become
depressed by a single st)ince, or a combination
of several sources, of mortalitv (Gasaway et al.
1983, 1992, Van Ballenberghe 1987). Based on
ol)servations in the Sierra Nexada, Wehausen
(1996) suggested that predation In mountain
lions has substautialK influenced the popula-
tion (lyuamics ol mountain s1uh'[i in part of the
wt'stern (ireat liasin. Kemoxal ol several moun-
tain lions was necessarx to preclude the extir-
pation of one population of these speciali/.i'd
ungulates (Bleich et al. 1991), and that popula-
tion of mountain sheep is sympatric w ith the
('asa Diablo deer popukition loi" part ol tlu-
year (Ta> lor 1991).

Given tlu' siuiilarities in causi'-specitic
mortalit) and the importance ol predation as a
cause of death among the populations wt' stud-
ied, till' potential loi' predation to ri-gnlate deer
populations might be retonsidered and lurtluM"
in\ cstigated, particiilarK lor nngratory deei"
inliabiting tlie aiid, unpredictable i'cosn stiMus
t\pical of the western (ireat Basin, in such sys-
t( ins [)redafion clearb is an important source
ol uiortalitN and ina\ assume greater iniiiortanee

1998]

Si m iNOHsiiii' \\i) ^l()Hl\l.ll^ oi \li i,i. l)i;i'.i{

271

'IaBLK 3. Painv ise coiiiparisoiis of sun i\()r.sliip fiiiicfioiis tor West Walker (WW), C^asa Diablo (CD), East Walker
(KW), Mono Lake (ML), aiul lino Momitaiiis (IM) imile deer i^opiilatioiis, Inyo and Mono counties, California, and
Douglas C^onnt)', Ne\ada. 19<S6-I994. (-lii-scjuare statistics are shown ahoxe the diatjonal; probabilities that sur\i\()rshiii
liuictious did not difler are shown lielow the diatjonal. I'or all coniixnisons, deyrees of freedom = 1.

Populatio

Chi-

scjuari' values

WW

i:w

Ml,

CD

l\!

7.B1I

4.235

2.458

4.977

<().()!

0.388

0.326

0.231

<0.()5

>().50

0.248

0.1.30

>0.10

>().50

XJ.50

0.012

<().05

>().50

>(J.5()

>().90

WW

i:w

ML
CD
IM

ProbabilitN that sun ixorship did not difTer

ill population limitation than in more mcsic
t ii\ ironments wlicic the effeets of climate aie
mofe tempered and more predictable.

In highly \arial)le s>stenis, densit\ -indepen-
dint e\ents (i.e., droughts and harsh winters)
occur unpredictahK (Mackie et al. 1990) and
can result in unanticipated population declines
that conlound conservation strategies. Nonethe-
less, density dependence would continue to
operate (McCullough 1990) in such systems
and could indirectK' affect predation rates
(McCullough 1979). Only through carefully
designed, long-term investigations, however,
\\ ill it he possible to reach meaningful conclu-
sions regarding effects of predation and other
sources of mortality on populations of migra-
ton deer occupving Great Basin ecos> stems.

Ac K XCnXLE DCM E XT.S

We thank T.E. Blankinship, W.E. Clark, J.H.
Da\is, D.A. Jessup, E.R. Loft, D.R. Racine,
T.L. Russi, R.J. Schaefer, R.A. Teagle, R.D.
Thomas, and numerous others for assistance
with captming and collaring nude deer; and
C.-L.B. Chetkiewicz, B.M. Pierce, D. Racine,
and R. Thomas for help recovering several
deer carcasses. R.W. Anthes served as pilot
during most telemetr>' flights, with occasional
assistance from L. Goehring and R. Morgan
(all of the California Department of Rsh and
Game [CDFG] Air Services Division). S.R
dejesus, the late J.D "Don" Landells, and B.K.
No\ak piloted the helicopter during capture
operations. We thank B.M. Fierce for assis-
tance with graphics and R.T. Bow>'er, M.W.
Oehler, Sr., J.D. Wehausen, and K.R. Whitten
for helpful comments on the manuscript. Prep-
aration of diis paper was supported by a Cali-
fornia Resources Agency Fellowship from the

University of California-Davis awarded to VC.
Bleich, and CDFC; Contract FG-1230 awarded
to T.J. Taylor. This research was fimded by
sportsmen and sportswomen of California
through their purchases of hunting licenses
and deer tags, the Fish and Game Advisory
Committee of Inyo and Mono counties, and
the Sacramento Safari Club. This is a contri-
bution from the CDFG Deer Herd Manage-
ment Plan Implementation Program and is
Professional Paper 002 from the Eastern Sierra
Center for Applied Population Ecology.

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Bleich, VC, CD. Har(;is, J.A. Keav, and J.D. Wehaisen.
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Great Basin Natur.\list

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tliL' \\ liitc-lino Hant;e, eastern {^aliloniia. L iii\er-
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Gasaway, W.C, R.D. Boehtje, D.V. C;ha.\(;.\ahu, D.C
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densities in Alaska and \Mkon aTuI implications for
conservation. Wildlife Monographs 120:1-59.

Gas.wv.'VY, W.C, R.O. Stephenson, J.L. Da\is, RK. Shep-
herd, AND O.E. BlRRis. 198.3. Interrelationships of
wolves, prey, and man in interior .\laska. Wildlife
Monographs 84:1-50.

Hornocker, M.G. 1976. The possihle influences of the
mountain lion on mule deer populations. Pages
107-109 in G.W. Workman and J.B. Low, editors.
Mule deer decline in the west: a symposium. Col-
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Logan.

Janz, D.W., AND I.W Hatter. 1986. A rationale for wolf
control in the management of the Vancouver Island
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of the Environment, Wildlife Bulletin B-45:l-35.

Kaplan, E.L., and R Meier. 1958. Nonparametric sur-
vivorship estimation from incomplete observations.
Journal of the American Statistical Association
53:457-481.

Knowlton, EE 1976. Potential influence of coyotes on
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man and J.B. Low, editors. Mule deer decline in the
West: a symposium. College of Natural Resources,
Utah State University, Logan.

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Kucera, T.E. 1988. Ecology and population dynamics of
mule deer in the eastern Sierra Nevada, California.
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Hnciiid 20 March IW)7
Accepted 23 Jdnncni/ /.9.%'

Crcat Basin N'atiinilisf 5S(3), © 199S. pp. 273-281

PERSISTENCE OE SUBALPINE rX)REST-ME ADOW ECOTONES
IN THE GUNNISON BASIN, C()L()KAD(J

Andrew |. Scliaiicr' -. Brian K. Wade', and jolin B. Sowcll'-^

Absikact. — Forests of tlu' southeni Hockv Mountains arc punctiiati'd 1)\ persistent meadows called parks that are
iloniinated by grasses and torlis. In an attempt to elucidate the maintenance of suhalpine parks in the Gunnison Basin, C>'ol-
orado, soil texture and tree moipholog\- differences along (iO-m transects spanning the forest-park ecotone were studied in
6 representati\e parks. Seedling sur\i\orship. percent seed germination, and soil moisture available to plants were also
studied along one of" the transects in \\'ill()w Park. .Soil analyses revealed 40% more silt and significandy less sand and clay
ill all n parks (P < 0.001), which supports the traditional Inpothesis that edaphic factors are involved in restricting estah-
lislnncnl of'tri'es in parks. In Willow Park ninislmc available to plants in soils at field capacity varied significantly across the
iiotone iP — 0.011), with oA^c more water in forest than in park soils. Measuri-s of growth rate obtained fiom tree height,
ilbh, and age were significantK higher nearer the ecotone (P < 0.001). The coefficient of'\ariation of" annual-ring width was
signiticanfK higher in forest than in ecotone trees (P = 0.002). These results suggest that stress of mature Engelniann
spruce {Picea ciif^chnannii) and lodgepole pine iPhm.'i contoiiu) is an unlikely explanation of park maintenance. P ciifichnan-
nii percent seed gennination and seedling sun ixorship were significantK higher in the forest than in the park (P < 0.001).
This ma\' be largeK due to the more se\ere seedling microclimate obseni'd in the park. Hesults indicate that limited
seedling establishment is priniariK resjionsible lor maintenance of subalpine parks in the (amnison Basin.

Key U()/y/.v. park, subalpine meadow, forest-meadow ecotones, Picea engehnannii, soil Icxiiirc. scedlin<i cstalilishment.
seed termination, soil moisture. Gimnisou Basin. Colorado.

MoiitaiK' antl .sul)alpine forests of the south-
ern Rocky Mountains are punctuated with
meadows dominated by grasses and forbs and
\aning amounts of sage {Artemma spp.), willow
(SV///.V spp.), and sedge {Care.x spp.). LocalK'
these treeless areas are called parks and range
from < 1 ha to thousands of hectares in size. In
C^olorado, parks form ecotones with pondei"osa
pine iPinii.s pondcrosa) forests in the montane
zone and mainly lodgepole pine (Piniis con-
foiia), Colorado blue spruce {Picea pini^ens),
and Engelmann spruce {Picea engehnannii)
forests in the subalpine zone.

E.xplanations for the presence of parks are
numerous, but many are not supported by
empirical e\'idence. Severe disturbances such
as fires and logging may allow the initial for-
mation of parks (Daubenmire 194.3, Kmamoto
and Bliss 1970, Koterba and Habeck 1971, \'ale
1981, Lynch 1995). Once established, they
ma>' be maintained b\ a number of biotic and
abiotic factors that may prevent the survival of
mature trees, but more frccjucntK cited is the
pre\ention of seedling establishment (Klikoff
19(i5, \h)ir 1967, Dunwiddie 1977, Taxlor 1990,

Doering and Reider 1992, Woodward ct al.
1995). Herbivorv (Klikoff 1965, Noble and
Shepperd 1973, Vale 1981, Cantor and Whit-
ham 1989) and seedling competition with her-
baceous vegetation (Robbins 1918, Feet 1988,
Coates et al. 1991, Comeau et al. 1993, Burton
and Bazzaz 1995) may be more prevalent in
meadows than in neighboring forests. Adverse
climatic conditions, such as more extreme tem-
perature fluctuations, may also limit seedling
establishment in parks (Pearson 1913, Kmamoto
and Bliss 1970, Franklin et al. 1971, Taylor
1990, 1995, L>nch 1995, Woodward et al.
1995). However, if these were the onl\ factors
involved, tree invasion into parks would be
expected as a result of enhanced seedling sur-
vival in the more mesic environment near the
ecotone (Daubenmire 1943).

A commonh cited factor for the maintenance
of forest-meadow ecotones is soil texture
(Robbins and Dodds 1908, Pearson 1913,
Dunnewald 1930, Ives 1942, Daubenmire
1943, Feet 1981, Veblen and Lorenz 1986,
Doering and Reider 1992). Unlike other pro-
posed explanations, which include factors that

'BioIuj;\ DipurtiiR-nt, Wtstem State College, Gunnison. CO 812.31.

^Present address: Department of Biological Sciences, University of Den\er, Denver, CO 80208.

•'Corresponding author.

273

274

Great Basin Natl kalis r

[Volume 58

are moderated at tlie ecotone, soil texture is
not readiK modified by the forest. Thus, soil
texture differenees between forest and park-
may be eapable of preventing tiee eneroaeh-
ment. Daubenmire (1943) eoneluded diat eoni-
fers of the Roek\' Mountain retiiion are acKeiseh'
affeeted 1)\' some faetor assoeiated with tine-
textured, eompact, or poorly drained soils. Fine-
textured soil may impede root elongation, pre-
venting the seedling root from reaehing sub-
surfaee moisture in a timeK fashion (Dauben-
mire 1943, Patten 1963). Fine-textmed soil may
also retain soil moisture at higher tensions, thus
deereasing soil moisture available to plants
(Patten 1963). However, e.xeessive drainage due
to coarse-textured soil has been suggested by
Pearson (1913) as a limiting factor in Arizona
parks.

Parks are frecjuent at 27()0-.35()() m elevation
within the Gunnison Basin, Colorado. Park eeo-
tones with P. contorta forests and P. engelmannii
forests are most common, but quaking aspen
[Populus tremidokles) also appear regularh
throughout the basin. The purpose of our
study was to elucidate the persistence of parks
in the Gunnison Basin by examining suggested
explanations of paik maintenance. The 1st ob-
jective was to ascertain whether established
trees at coniferous forest-park ecotones are
stressed compared with trees in the forest
interior Such stress would suggest that limit-
ing factors are operating on mature trees, and
such factors may limit tree advance into parks.
Stress would not be expected if parks are pri-
marily the result of inhibited seedling estab-
lishment. The 2nd objective was to document
P. enf^eimannii seed germination rates and seed-
ling survi\'orship across the forest-park eco-
tone. Inhibited germination and reduced sur-
vivorship would be expected if limited tree
establishment is maintaining i^arks. The 3rd
objective was to document soil-texture and
water-holding characteristics across coniferous
forest-park ecotones. The presence of soil-tex-
ture gradients across park boundaries would
support the contention that edaphic factors
Iia\ (• a lolc Ml iiiaiiitaining paiks in I lie ( iiii mi-
son Basin.

\l viini \i,s \\i) Mi;tii()I)s

,Slii(l\ Sites

We selected 6 jxiiks to icpresent the diver-
sity of coniferous forest-park ecotones in the

Gunnison Basin (Fig. 1, Table 1). Two transects
spanning the forest-park ecotone were estab-
lished in each park. Transects were located in
more pristine areas awa>' from obvious distur-
bance and liuman activities. These 60-m tran-
sects were oriented perpendicular to the eco-
tone boundarx and extended 30 in into the for-
est and 30 m into the park. Sampling occurred
at the ecotone (0 m) and at 15 m and 30 m into
both the forest and park. We randomly chose 3
soil sampling sites along a 30-m line oriented
parallel to the ecotone at each of these dis-
tances. Similarly, we chose 3 trees at 0 m, 15 m,
and 30 m into the forest to obtain tree-growth
measurements for stress analysis. One transect
in Willow Park was utilized to accjuiie data on
seed germination, survivorship of 3-> r-old P.
engelmannii seedlings, seedling microclimate
regimes, and moisture available to plants in
soils at field capacity.

Tree Morphology

Reduced tree growth, or stunting, was used
to measure relati\'e tree stress. Tree-growth
parameters of 3 randomh' selected trees weie
measured along the transects in all 6 parks at
the ecotone (0 m) and at 15 m and 30 m into
the forest. The diameter-at-breast-height (dbh)
and height of each tree were measured, and
each tree was cored at breast height using a
Swedish increment borer oriented peipendic-
ular to the slope. Cores were treated and ana-
Kzed according to Fritts (1976), \ielding tree
age and axc-ragc annual-ring width. Stunting
was discerned 1)\ lower height:age, (ll)li:ag(\
and height;dl)h ratios or narrower age-adjusted
average annual-ring widths. Increased tree
stress may also be indicated b\ a higher coeffi-
cient of variation resulting from greater sensi-
ti\it\ to climatic \ariation. 'Hie coefficiiMit of
xariation (standard dcxiation divided by tin-
mean) of tree-ring width was calculated using
the age-adjusted axcrage annual-ring widths
for the last 10 > r ( 19S3-1992). For eacli grow lli
parameter (dependent xariabie). we used a
nested AN()\'A (tiansects nested williin parks)
to lest tlic null hypothesis that location along
the- transect (proxiniitx to the ecotone) has no
effect on ti'ci' growth.

Seedling [""stahlishnu'iit

To (locnmcnt the inlhicnif ol the paik cn-
\ ironmenl on seed germination and establish-
ment, we located three 4()-in rows, orii'uted

998]

Si lui i'i\i; Fohkst-Mkadow Ecotonks

275

Taiui: 1. Di-stiiptiM- siiiiiinan ol tin- (i iri)r(s(iilali\(' parks in (lir ( .iiiiiiisdii liasin, (Colorado

Park

Latitude and
lonjiitiidf

Kk'\ati()n

(m)

Si/.f

(ha)

Soil parent
material

Dominant forest
species

Bit; Willow 3.S°14'\, 1()7°2()'\V

Taylor

I iiidii
Willow

38°50'\, 106°35'W

3450

Hill. 38°06'N, 106°52'VV 3328

l'oipli\r> 38°29'N, 106°21'W 3280

2938

38°47'N. 1()6°33'W' 2987
38°04'N, 106°55'W 3475

160

370
15

1110

800
(iO

basalts, tuffs, \olcanic
conglomerates

ash How luffs

granites

glacial and outwasl
deposits

Picea eniichnannii

Picea eniicliiKtnnii

Picea en^elinauiiii
and Pinus c(mtoii(i

Piiiu.'i conturla

Pinit.s amtortd

andesiti-s. welded tuffs Picea enoelmunnii

CRESTED

\

■^'

BUTTE o

k

Taylor Park

\

T,

<^\ln\on

{Cottonwood

»

^

r Park

\ Pass

Spnng Creek

Pass ^- "

JUAH MTS.

Fig. 1. Location of the 6 representati\e jiarks within tin
Gunnison Basin, Colorado.

parallt'l to the ecotone, in Willow Park at 30 m
into tlie forest, at the ecotone (0 m), and at 30
in into the park. At 1-m intervals along the
rows, we established 0.5 x l.O-ni seedbed giids,
di\ided into 50 equal 100-cni- sections, to
facilitate the sowing and subsequent locating
and monitoring of seeds. On 9 June 1994, 25 P.
en^clinaiinii seeds were sown into the first 25
axailable sections. If rocks or surface roots
prexented a seed from being sown in a partic-
ular section, we utilized an alternate section.

Seeds recei\ ed 100 ml of water upon sowing
and an e(]ual amount twice a week for 3 wk.
Germination and smvixorship were noted
weekK until 9 October 1994 and again from
24 July to 23 September 1995. A chi-square
analysis was used to test the null hypothesis
that there were no tlifferences in seed germi-
nation rates across the ecotone boimdan-.

Seedling sur\'i\ orship was monitored using
3-\ r-old nursery-grown P. engehnannii seedlings
(Lawyer Nursery Inc.). On 9 June 1994 we
planted seedlings eveiy 0.25 m along the same
40-m rows unless obstructions such as rocks
were present. Seedlings received 160 ml of
water, approximately equal to 20 mm of pre-
cipitation, t\\'ice a week for 3 wk to facilitate
establishment. Seedling sunix orship was noted
weekly until 9 October 1994 and on 10 Jul\'
and 23 September 1995. A chi-s(juare analysis
was used to test the null hypothesis that there
are no differences in seedling sin\ i\ al across
the ecotone boundaiy.

Differences in seedling microclimates and
potential causes of seedling mortalit\ were
assessed b\ logging weekl\' niitximum and min-
imum temperatures 20 cm below the surface,
at the soil surface, and 2 cm abo\ e the smface
at the ecotone (0 m) and 30 m into both the
forest and park in Willow Park from 9 June
through 9 October 1994. Precipitation was also
measured weekly at 30 m into the park during
this period.

B\' germinating 72 P. engehnannii seeds and
growing them in a greenhouse utilizing soils
collected in ^\■illow Park, we ascertained the
influence of forest, ecotone, and park soils on

276

Great Basin Naturalist

[Volume 58

root elongation and thus the potential for
seedlings to reach subsurface moisture. Soils
were collected to 30-eni depth at the ecotone
(0 m) and 30 m into both the forest and park.
The 2.5 X 20-cm tubes with seeds sown at 5-
mm depth were watered daily. We harvested
shoots and roots of 15-wk-old seedlings and,
after measuring their lengths, dried them at
70°C. Root lengths and diy weight rootishoot
ratios were analyzed using a one-way ANOVA.

Soil Analyses

Soil samples were obtained from a 2-cm-
diameter core of soil extending from the sur-
face to 30-cm depth along both transects in all
6 parks. The core excluded the O horizon.
Soil-texture analysis was conducted for each
core using the hydrometer method (Day 1965).
Hydrometer readings were recorded at 0.5, 1,
2, 4, 8, 15, 30, 60, 120, 240, 480 min to con-
struct soil particle-size distribution cui-ves, and
differences in percent sand, silt, and clay among
locations along the transect were analyzed
using a nested ANOVA (transects nested within
parks).

Moisture available to plants in soil at field
capacity was measured for 3 randomly selected
soil samples collected at the ecotone (0 m) and
30 m into both the park and forest in Willow
Park. Using a 1.5 MPa ceramic plate extractor
(Soilmoisture Equipment Corporation), we
measured soil water content at 0.010, 0.033,
0.5, and 1.5 MPa. Soil moisture a\ailable to
plants was calculated utilizing the difference
between water content at field capacity and at
the permanent wilting point. These values are
most closely correlated to water contents at
0.033 and 1.5 MPa, respectively (Peters 1965,
Banister 1986). Differences in soil moisture
available to plants among locations were ana-
lyzed using a one-way ANOVA.

|{i':si'i;is
I'vvc Morphology

Two of the 6 parks studied, Taylor Park and
Union Park, were surrounded 1)\' serai /! con-
torta loresl. Tree morphology along the /! C(»i-
lorta transects often exhibited excciifious lo
the consistent trends obscrxcd in l\\c I] i'n<!,cl-
niannii forests surrounding the other 4 parks.
IIeight:age, dbh:age, and hcighlulbli ratios,
whi'u all 6 parks were included, indicated sig-
nificant interactions between parks and loca-

tions across the ecotone {F = 0.005, P < 0.001,
and P = 0.005, respectivcK). Therefore, Ta\'lor
and Union Park data were excluded from fur-
ther analyses and the consistent trends ob-
served in the P. engehnannii-dimnivdtt'd eco-
tones are reported below.

P. engehnannii at the ecotone had a signifi-
cantb higher heightiage ratio (F < 0.001) and
dbhiage ratio (F < 0.001), indicating more
growth per year (Fig. 2). The height:dbh ratios
showed that trees at the ecotone had grown
more in girth than in height relative to trees in
the forest interior (P < 0.001) (Fig. 2). Trees at
the ecotone had a significantK lower coefficient
of variation of tree-ring width (F = 0.002), in-
dicating less year-to-year variation in growth
increment (Fig. 2).

Seedling Establishment

At all 3 locations (forest, ecotone, and park)
in Willow Park, no germination of sown seeds
was noted in the 1994 growing season. Germi-
nation did occur in the 1995 growing season
and was significantly higher in the forest
(46%) than in the ecotone (28%) and park (5%;
P < 0.001). Of the seeds that did germinate,
total seedling sur^'ivorship at the end of the
season (23 September 1995) was 18%, 32%,
and 42% along the forest, ecotone, and park
transects, respectively (Fig. 3). These seeds,
tested in vitro in 1994, had a 93% germination
rate.

Smvivorship of planted 3-\ r-old P. engcl-
mannii seedlings was significantK higher in
the forest (50%) and at the ecotone (52%) than
in the park (8%) after 15 mon (P < 0.001; Fig.
4). While the primar\- cause of mortalifx
appeared to be desiccation during the 1994
growing season, 73% of seedlings in the forest,
55% at the ecotone, and 0% in the park experi-
enced herbi\()r\. Remoxal of leader shoots
during the winter accounted for most of the
observed herbixoi).

Seedling microcliiuatc (luring the 1994
growing season was more se\ I're in the jxuk
than the forest. Nhiximum and miniuHnn soil
tcnipeiatuics at 2()-cin di-plh were similar
across the ccotouc. llowcNcr, at the soil sur-
lace and at 2 i in aboM' the surface, seedlings
in the park were consisteulK exposed to colder
nights and warmer da\ s comparetl lo scihI-
liiigs within the f'ori'st (i'"ig. 5). i^ecipilation
exhibited a pattern t\ pical of the (iuuuisou
liasin, with a relativeh dr\ June follow t-d b\

1998]

Si H\i ri\i: Im)Hi:st-Mi \i)()\\ Ecotones

277

0 3 -I

30 m in Forest -j-

15 m in Forest J_

Ecotone

Taylor

Union

Big Porphyry Willow

Blue

Park*

Park-

Willow Park Park
Park

Park

Fig. 2. Height:age ratio. cll)li;agf ratio, }ieiglit:dbh ratio,
and coetlicient of variation of tree-ring width of trees near
tlie forest-park ecotone in I'inits confoi-ta (*)-doniinated
and Picea rn^('///irtn;H/-dominated treelines. Bars indicate

standard errors (n — 6).

increased precipitation bronglit Iw afternoon
tluniderstorms in July and August.

P. engehnonnii seedlings grown in forest,
ecotone, and park soils showed no observable
differences in growth. The mean root length of
seedlings grown in forest (14.1 cm), ecotone
(13.7 cm), and pai'k (14.6 cm) soils did not differ
significand\' [P = 0.534). Dn' weight root:shoot
ratios of seedlings grown in forest, ecotone, and
park soils were 0.67, 0.69, and 0.70, respectixe-
1>, and did not differ significandy (P = 0.764).

Forest

■ 24 July Cohon
n 1 1 Aug Cohort
D 26 Aug Cohort

(D

E

13

23 Sept

24 July 11 Aug

26 Aug

25

Park

24 July

11 Aug

26 Aug

23 Sept

23 Sept

Fig. 3. x\nnil)er of seeds germinated and sur\ ivorsliip of
those seedlings in \\'illo\\ Park. The 3 cohorts account for
those seeds that germinated prior to 24 |ul\ 1995, between
24 Jul) and 11 August 1995, and between 11 August and
26 August 1995.

100 n

80

Q.
Ui

o

>

D
CO

60 -

40

20

— O— Forest
Ecotone
Park

June July Aug Sept Oct
1994

July Aug Sept
1995

Fig. 4. Percent sun i\al rate of 3->T-old seedlings planted
9 Jime 1994 along a transect spanning the forest-park eco-
tone in Willow Park. Numbers of seedlings planted in the
forest, ecotone. and park were 122. 145, and 160, respec-
tively.

278

CiRKAT Basin Nail ralisi-

[\blunie 58

O

o

<u

Q.

E

0)

H

60

40

20

-20
60

40

20

-20
60

40

20

-20

Clay

Silt

Sand

Soil Surface

Forest (Max)
Forest (Min)
Ecotone (Max)
Ecotone (Min)
Park (Max)
Park (Min)

20 cm Below
Soil Surface

July

August September October

Fig. 5. Weekly maximum aiul minimum temperatmcs at
3 different loeations witliin the seedlings mieioelimate
along a transect spanning tlie forest-park ecotone in \\ il-
low Park, 'lemperature extremes were recorded weekly
from <J June throiigli 9 Oetoher 1994.

Soil Analy.scs

VVliik' soils ill all () parks were saiuK loams,
soil textiiif (liUcrc'd siunilkaMtly {F < O.OOl)
across the torcst-park ecotone. Forests liad a
mean of 8% more sand, 53% less silt, and 72%
more cla\ compared with parks (Fit!;. 6). Mois-
ture available to seedlings in soils at licld
capacity also dillered siKnilicaiitK (P = 0.01 1)
across the lorest-park ecotone. There was 54*^/^
more water available to plants in lorest soils at
field capacitv than in ])ark soils at licld capac-
ity(Fig.7). ■

100 1

C 80

o

O 60

E
o

O 40

o

CO

>.o 20

IMII

30 m 15 m
Forest

Ecotone

15 m 30 m
Park

Fig. 6. Soil textme along transects spanning the forest-
jiark ecotone. Percentages are the means of 6 parks with 2
transects per park and .3 replications per location Oi = 36).

Discussion

Tree morphology data indicated that stress
of mature trees is an unlikely contributing fac-
tor to maintenance of forest-park ecotones in
the Gunnison Basin. Trees at the ecotone
appear no more stressed, possibly even more
robust, than trees farther into the forest. The
lower coefficient of \'ariation of tree-ring width
found in ecotone trees indicates less year-to-
year \ ariation in growth increment, suggesting
a more imiform and less stressful environment
(Fritts 197(i). These results indicate that fac-
tors limiting seedling establishment con-
tribute to the maintenance of parks in the
(immison liasin, which corroborates the ccin-
clnsion of Dunwiddie (1977) pertaining to
meadows in Wyoming.

Seed germination and seedling siir\i\()r-
ship of P. t'n<^elni<iiuiii wvvc restricted in \\ il-
low Park, which Inrther supports tlu' con-
tention that parks arc maintained In limited
establishment. The higher mortalit\ of si'cdlings
in the park may be due in part to the more
exircnu' microclimate. Icmpciatiirc twtii-nu'S
pla\ an important role in the siii\i\al of P.
(■ii<^cliii(iinui seedlings (I'atten 19(i.'), Knramoto
and Bliss 1970, I'Vanklin et al. 1971, Boot and
llabeck 1972, Noble 1973. Moir and ilnckaln
1991, Baliskx and Burton 199,1, Tin lor 1995,
Woodward et al. 1995), and the large diurnal
llucluations in surface and air temperatures

19981

S L h.vi .I'l \ I". F()Ki':s'i"-M KAi)( )w Eco r( )\Ks

279

0.3 1

0.2

5

T3

O
(/)

o

X

05

^ 01

0
CO

03
>
<

0.0

T

T

T

J

30 m 15m

Forest

Ecotone

15m 30 m

Park

Fiij. 7. Moistiiiv available to plants in soil at fielcl capac-
it> tor saniplfs colkxtfd alons^ tlu' transect spanning the
toiest-park ecotone in \\ill(n\' Park. Available Tnoistiire is
the tlifk'rence !)et\veen water content at lield capacity* and
water content at the wilting [loint. Bars indicate standard
errors (n = 15).

common to meadows may inhibit tree invasion
(Hellmers et al. 1970, Jakubos and Romme
1993). During the 1994 growing season, tem-
peratures 2 em al)o\e the soil surface in Wil-
low Park fluctuated greath; with a mean weekK'
ma.ximum of 43°C and a mean weekK mini-
mum of — 8°C. Such temperatme fluctuation
alone may pro\e fatal to P. engchnaimii seed-
lings. Hellmers et al. (1970) noted 09c surxixal
of P. engcliiumiiii seedlings grown in high day
(35°C) and low night (3°C) temperatures. In
addition, terminal bud fomiation was inhibited
in high da\' temperatures of 35°C (Hellmers et
al. 1970), which may increase mortalit\' during
the subseciuent winter Precipitation and tem-
peratiuvs for the 1994 and 1995 growing sea-
sons were near normal at Lake City, Colorado,
36 aerial km west of Willow Park, indicating
that weather data we recorded in 1994 were
not unusual (United States Department of
Commerce 1994, 1995).

HerbivorA' in parks could potcntialK limit
establishment in subalpine meadows; ho\\t'\er,
herl)i\()r\ alone does not appear to maintain
the ecotone in Willow Park. Although seed
herbivor\' b\' members of the seed bug family
(L>'gaeidae) was observed in 1994, preliminary
obsenations of predation rates of seeds placed
in wire-mesh containers at forest, ecotone, and

park locations indicated that the potential for
such herbixory was uniformK' high (9()-l()()%)
across the ecotone. Hemoxal of P. cniichndiinii
cot\ ledons or terminal buds by hcrbixorcs
may limit regeneration (Noble and Shepperd
1973, Noble and Alexander 1977), although
the impact of shoot herbixon in Willow^ Park
appears limited considering the observed dam-
age of P. eugchnannii seedlings was greatest
in the forest where survivorship was highest.
Cantor and Whitham (1989) suggest that aspen
is excluded from meadows due to below-
ground herbixor) by pocket gophers. Below-
ground herbivory by rodents, as indicated b\'
soil moimds, accounted for a small portion ol
the P. engehiuiniiii seedling mortalitx in Wil-
low Park.

Variation in soil texture across the forest-
park ecotones supports conunonK cited sug-
gestions that edaphic factors help maintain drx'
Rocky Mountain parks (Daubenmire 1943,
Peet i988. Knight 1994). Fine-textured soils in
parks are more favorable for growth of sod-
forming herbaceous vegetation, which may
competitively exclude the establishment of tree
seedlings (Stahelin 1943). However, if such
competition were the primarx factor maintain-
ing parks, the treeline would be expected to
advance into the park where shading from
ecotone trees inhibits herbaceous x'egetation
(Daubenmire 1943). Park soils may increase
tree seedling mortality bx enhancing water
stress. Fine-textured soils max slox\- xxater infil-
tration and thus increase drought severitx'
(Knight 1994). Daubenmire (1943) suggested
that inhibited root elongation in park soils
increases susceptibility of tree seedlings to
drought; this premise is not supported by our
study where root growth was unaffected by
soil textme. In Willoxv Park, park soils at field
capacity do have less moisture axailable to
plants, thus enhancing the potential lor xxater
stress, particularly in earlx' summer x\ hen prc-
cipitatiou is minimal.

Factors limiting seedling survival can be
hirther elucidated by observing the few loca-
tions where trees do establish in parks. Estab-
lished trees in Willoxx Park are often xxell away
fiom the ecotone and iuex itably associated xxith
willows {Salix spp.), xvhich may be providing a
mesic microclimate that facilitates tree estab-
lishment. Rochefort and Peterson (1996) found
tree inxasion in sul)alpine meadows in the
Olympic Mountains to be associated with

280

Grkat Basin Naturalist

[\'()lume 58

heath-shrub communities that ma\ moderate
soil temperature and moisture. On the other
hand, the presence of willows max be indica-
tive of moist soils that could promote seedling
survival despite unfavorable soil texture.

Supporting the role of edaphic factors oxer
climatic factors is the often prolific establish-
ment oi P. en^ielinarmii and P. contoiia obsened
in clear-cuts near the parks. Notable is Blue
Park, where recent clear-cuts reached the
forest-park ecotone. Here the ecotone appears
to be maintained as P. contoiia is regenerating
only in previously forested areas. This indi-
cates that while the climate is suitable for
seedling establishment, it is the soil or the
associated vegetation in parks that maintains
forest-park ecotones in the Gunnison Basin.

Acknowledgments

We thank William H. Romme and Richard
G. Reider for their review of the manuscript
and helpful comments. This research was
funded in part b> a Thornton Biology Research
Grant.

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Received 20 jmiuanj 1997
Accepted 29 Sepleinher 1997

Great Basin Naturalist 58(3), © 1998, pp. 282-284

COMPARISON OF THE EPIPROCT STRUCTURE OF TWO
CLOSELY RELATED SPECIES, SWEUFSA FIDELIS (BANKS) AND
S. REVELSTOKA (JEWETT) (PLECOPTERA: CHLOROPERLIDAE)

JiMiniler K. Dt'Ik'. Mar> Jane Kilgore', and Bill 1^ Stark'-2

Abstiuct. — The male epiproets of 2 closely related western Nearctic species, Sicclt.sa jidclis (Banks) and S'. ;Yrt7-
stoka (Jewett), were examined using SEM. The males of these 2 species have been historicalK' distinguished l)\' epiproct
measurements. The ratio of the length from the base to greatest width versus total epiproct length ranges from 0.49 |ini
to 0.67 |im (.V = 0.56) in S.fidelis and 0.55 |lm to 0.69 |am (x = 0.60) in S. revebtoka. Similarities in measurement sug-
gest that the location of the greatest epiproct \\idtli is not a reliable and consistent character for distinguishing males of
these 2 species.

Key words: stumjlij, Sweltsa, epiproct, uiorphologij, SEM, western North America.

Swcltsa fidelis (Banks) and S. revclstoka
(Jewett) are similar western Nearctic species
with broadly overlapping geographical ranges
in the northern Rocky Mountains and Cas-
cades. Jewett (1955) noted that only a "slight
difference" in lateral aspect of epiproct shape
distinguishes males of the 2 species, although
females are easily separated b)' subgenital
plate shape (Surdick 1995). Jewett (1955) and
Gaufin et al. (1972) suggested the S. fidelis
epiproct was "about 1.7 times as broad near
the tip as . . . near the base, whereas the
epiproct oi S. revclstoka was "less broad near
the tip." Baimiann et al. (1977) found the dor-
sal aspect of the epiproct tip of S. jidelis to be
almost "twice as broad as base in dorsal view,"
and in .S. revelstoka the tip was considered
about tlic same width as the base. Surdick
(1995) abandoned these characters in favor ol
the location of die greatest epiproct width as a
means of separating males of these species,
the greatest width occurring at 3/5 length in S.
fidelis and at 3/4 length in S. revelstoka. This
method also proved to be unreliable for distin-
guishing the males of these 2 species.

.\1 Ali'.Hl AI.S ,\\l) Ml'.niODS

Spcfiinciis cxaniincd arc Hslcd in laMc 1.
Each collection was identilied to species 1)\ tlic
examination ol associated lemale specimens.

Epiproct samples were taken b\ severing the
last 4-5 abdominal segments from male speci-
mens that had been stored in alcohol. Samples
were placed in acetone and cleaned with an
ultrasonic cleaner for 1 min. Samples were air-
dried, placed on double-stick copper tape on
SEM stubs, coated with gold palladium, and
scanned using an AMRAY Model ISIO SEM.
The length to the widest point and total length
of the epiproct were measured using the "click
and drag" function of the AMRAY computer
control software. Results are presented in
Table 2.

Results .\\d Discussion

Figures 1-4 indicate the close similaritx in
epiproct structure for S. fidelis and S. revel-
stoka. In dorsiun, the S. fidelis epiproct (iMg.
1) appears wider than that ol S. revelstoka
(Fig. 3), but this difference is not supported l)\
measurements. The range ol widths present in
S. fidelis specimens is 115-177|am (.v = 147. (i
|am), wliicli is fomixiiable to the spectrum ol
widths in S'. revelstoka, SI. 1-1 SO |Llm [x =
109.9 lam).

The ratio of the length Irom the base to the
point of greatest width xcisus total length ol
(■|)ipi()ct langes from 0. 19 |.lni to ().(i7 |.lni (.v =
0.50) in S. fidelis and lioui 0.55 j.lm to 0.(i9 \.[u\
{x = 0.00) in S. revelstoka. Similarities in

'BioloRy Ocpartmcnt, Mississippi C;()lleKc. Cliiilc.ii. \IS :W().5H.
^Address all correspoiidfiice to tliis atitluir.

282

1998]

Comparison of Two Spkciks oi Swi.ltsa

283

Tabi.I. 1. l.ocalitx (lata lor Swcltsd fidilis ' Banks) and S. rcielstoka (Jewett).

SucltsaJklelLs

SucltSi

[■Lstokd

2A.

ID: Li-nilii Cio., Moose Crt-ek hlw Lost Trail
Pass, 23-\I 1-1979, B. Stark. K. Stiwart.
R. Baiiinann, 56 .59

M T; Callatiii Co.. I Kalilc Cri'ik. Il\alitr

S(ivia\v Ciffk Tiailhead, 24-\"il-1979.

B. .Stark, K. Stewart, R. Baiiniann. IcJ, 75

3A. MT; C;allatin Co.. Portal C:ret>k. FS 9SI,

6miN BigSk-%-, 9-\I-19S7. B. KondraticIV,
6c?. 19

4A. Ml: (ilaeici' (^o.. Swilt ( Jiiicnt Creek near
Red Roek Fails. S-\Il-19(i7. \l. Miner,
AS, 19

5A. MT: Cranitc Co.. Butte Cahiu Creek,
26-\"ll-1979. M. Miner. 44(5,50 9

6A. OR: BeTitoii Co.. Parker Creek. Man's

Peak Road. 2(>\I-19S.5. B. Stark, lid, 169

7A. OR: Lane Co., 12.5 mi N Blue River

.Andrews E.xp. Forest, 6-\TI-197S, B. Frost,

2d, 29

8A. \\'.\: Spokane Co., Deadman Creek,

Mt. Spokane St. Pk., ll-VI-1991. B. Stark,
R. Banniann. 7d.4 9

1 B. AB: Banir Nat. Pk., Moraine Creek,
27-\ll-1972, A. Ciaufin. 4d,39

2B. M T: (ilaeierCo.. leeherti Lake. (;laeier
Nat. Pk..21-\l 1-1979, B.Stark,
K. Stewart. R. Bauniann. Id, 29

3B. OH: Clackamas Co.. Still Creek

Campi^round, Mt. Hood, 12-VH-1979,
B.Stark. K.Stewart, 7d, 39

4B. OKI lood River Co.. Salmon River

trilnitan. Mt. Hood. 13-\ll-1963. S. lewett.

4d.29

5B. \\ .\: Pierce C^o., St. Andrews Creek,
-Mt. Rainier Nat. Pk., 13-VH-1979,
B. Stark. K. Stewart, 16d, 10 9

Table 2. Epiproct measurements in \xm for Swcltsa
fidclis (Banks) and S. revelstoka (Jewett). LGWTTL =
epiproct lens^tli to the point of greatest width di\ided 1)\
total epiiiroct length.

Site

S. fidclis
lA
2A
3A
4A
5A
6A
7A
8A

S. revcLtoka
IB
2B
3B
4B
5B

#

LCWriL

2

0.49-0.50

1

0.57

2

0.56

1

0.52

8

0.52-0.67

1

0.56

1

0.59

2

0.58-0.60

X = 0.56

2

0.57-0.60

1

0.55

2

0.60

3

0.60-0.61

8

0.56-0.69

X = 0.60

mea.suremeiits and the broad range present in
both species suggest this character is not a
consistently rehable means for distinguishing
tlic 2 species.

Kicker (1939) and Frison (1942) record
brachypterous males and females of S. fidelis,
and Jewett (1955) describes both long-winged
and brachxpterous S. revelstoka adults. .Siu--
dick (1995) reports that S. revelstoka "coni-
nioiiK exhibits different degrees of braclnp-
tcr) while S. fidelis "is usually macropterous. "
In the present stiicK' all S. fidclis (n = 18)
males were long winged, and 10 S. revelstoka
males [n = 16) were brachypterous. These
reported \ariations in wing length also bring
into question the reliabilit\' of this character
ibr distinguishing males of S. fidelis and S.
revelstoka. \o synonymy is suggested for
these species at the present time because the
female subgenital plates are so different, but
distributional records based on isolated male
specimens should be considered tentative
until \erified with female specimens.

284

Great Basin Natuhalist

[Volume 58

Fi^s. 1-4. Scamiinti electron rnicio'^raphs ot Sucltsd I'piprocts: 1, S.Jklelis, dorsal aspect; 2, S.Jidcli.s, lateral aspect; 3.
S. revelstokd. dorsal aspect; 4, S. rcvcl.slokd, lateral asjiect.

ACKNOWLKDGMENTS

We thank B.C. KoiKlnitielT (Colorado State
Universityj, K.\V. Bauniann (Brigliain Young
University), and C.R. Nelson (University of
Texas) for their generous loan of specimens.
This study was supported in part by the
Howard fluglK's .Medical Institute, Under-
graduate Biological Sciences Education Pro-
gram Crant #71195-538901.

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western North American stoneflies (Plecoptera).
Wasmann Journal of Biolos^x' 13:14.5-155.

Hl( Ki;n. W.E. 1939. A preliminaiy list of stoneflies (Ple-
coptera) from the \ icinit\ of C]nltns Eake. British
Columbia. Proceedings of the Entomological Soeiet\
of British C;()luml)ia 35:19-23.

Sl'KDK.k, R.E 1995. New western Nearctic Sucltsa (Ple-
coptera: (;hloroperlid;ie). Proceedings of tlie Ento-
mological Societ\ ol Washington 97: l(il-177.

Recchril 2H Aufiiust 1997
Accepted 27 Septetnber 1997

C;re:it Basin Naturalist 58(3). © 1998. pp. 285-288

STAH\ ATION AND NKSTLINC ElECTION AS SOURCES OF
MOm ALITY IN PAlUSn IZED LAZULI BUNTING NESTS

William 15. Davison'
Key iLord.s: brood pumsitis}n. iwslliitfS, <!,ri>ivtlt. Brown-licadcd couhird. Molotliiiis atcr, ho.st-fuirasiie iiiteraclion.

Main .stiKlifs liaxc docunu'iitcd a reduction
in hcst nestling growth and the number of
fledglings produced from nests of small hosts
parasitized h\ Brown-headed C>'o\\i)irds {Molo-
thrws (Iter- Nolan 1978, Scott 1979. Hatch 1983,
re\ie\ved in Ma\ and Robinson 1985, Nhu^xil
and Cruz 1989, Weatherhead 1989). A short
incubation period (Nice 1953, Nolan 1978,
Lowther 1993), loud begging calls (Friedmann
1929, Dearborn 1997), and larger relative
mouth sizes (Ortega and Cruz 1991), coupled
with a rapid growth rate (Norris 1947, Scott
1979, Hatch 1983, Lowther 1993), typically
gi\e the cowbird nestling a head start over
host \oung. As a result, the larger cowbird
nestling gapes higher than most host nestlings,
which increases the probabilit) of the cowbird
being fed by host parents (Smith and Mont-
gomerie 1991, Teather 1992, Leonard and Hom
1996). Thus, one potential cause of reduced
reproductive success in parasitized nests of
small host species could be a disproportionate
provisioning of food to the young cowbird,
resulting in stanation of host nestlings. How-
e\er, I know of onK a single stud\ (Dearborn
1997) documenting the distribution of food
among nestlings in parasitized nests.

In addition, se\eral studies ha\e implicated
cowbird nestling ejection behavior as a source
of host nesding mortality (Twomey 1945, Dear-
born 1996). Cowbird nestlings ejecting host
\()ung ha\e been \ideo taped once (Dearborn
1996) and suggested b\- at least 2 other re-
searchers (reviewed in Dearborn 1996). The
extent to which this behavior occurs is not
known, since most researchers assume miss-
ing host \oung are taken b\' predators or re-
moxed from the nest b\ parents after starAing.

in this stud\ 1 recorded feeding rates, size
of food items delivered, distribution of food,
and growth rates in parasitized and unpara-
sitized nests of Lazuli Buntings {Passerina
(unoena). I specificalK examined whether bunt-
ing nestlings in parasitized nests die due to
starvation or to ph\ sical aggression from the
cowbird nestling.

The primarx stud\' area is in western Mon-
tana in .Missoula (^ount\' on the western side
of Mount Sentinel and .Mount Jumbo. These
mountains are part of the Sapphire Range and
are located on the eastern edge of the cit\' of
Missoula. Elevations range from 1070 to 1719
m. Priman' habitat is Palouse prairie, consist-
ing of native bunchgrasses interspersed with
shrubs.

From late Ma\' to August 1995, I monitored
2 parasitized and 16 unparasitized nests on
Mount Jmnbo and Mount Sentinel and w eighed
dail\' (to the nearest 0.1 g) cowbird and bunt-
ing chicks using a Pesola scale. I conducted 2-h
l)eha\'ioral obsenations of parasitized and un-
parasitized nests from a distance of 20-30 m
using a \ariable-power spotting scope to record
nestling beha\"ior and the proportion of food
deli\ ered to cowbird and/or bunting nestlings.
The size (jf food items delixered to each nestling
was placed into 1 of 5 categories based upon
the following criteria: 1 = hard to see, 2 =
equal to bill length, 3 = just longer than bill, 4
= twice bill length, 5 = more than twice bill
length. Volume of food per hour delivered to
nestlings was calculated by multiplying the
number of feeding trips per hour by average
load size. Obsen ation times were selected to
ensure that parasitized and unparasitized nests
were obser\'ed during the same times of day
and under similar weather conditions.

'Di\ision of Biologica] Sciences. Lniversitv of Montana, MissoiiliL MT 59SI2. Present address: Department of Zooiog>. 60(J Lincoln .Vvenue. Eastern Illinois
Uni\ersit>. Charleston, IL 61920.

285

286

Gri-:at Basin Nati ii\ijs r

[Volume 58

I used a Mann-Whitne\' U test (Zar 1996) to
compare (1) da\ 3 weights of hunting uestlings
in parasitized and unpaiasitized nests, (2) aver-
age nestling weights per nest on day 3 in para-
sitized and unparasitized nests, (3) volume of
food per hour delivered to nestling cowbirds
and buntings, and (4) average lumiber of feed-
ing trips per hour for parasitized and unpara-
sitized nests. A binomial test was performed to
compare the proportion of feeding trips in
which onl\' the cowl)ird was fed to the propor-
tion of feeding trips in which just buntings
were fed.

The da\- 3 weight of Lazuli Bunting nest-
lings in parasitized nests {n = 5 nestlings) was
significantly lighter than the day 3 weight of
Lazuli Bunting nestlings in unparasitized nests
(n = 16 nestlings; Mann-Whitney U test, P =
0.()()()9). Recognizing that within-nest varia-
tion may confound this analysis, I then aver-
aged the day 3 weights for each nest. The aver-
age day 3 weight of Lazuli Bunting nestlings
differed between parasitized and unparasitized
nests (.V = L84 g ± L15 s and 4.28 g ± 0.349,
respectively; Mann-Whitney U test, P < 0.10).
Small sample size prevents significance; how-
ever, each of the 3-d-old bimting nestlings in
parasitized nests weiglied less than the light-
est 3-d-old bunting nestlings in unparasitized
nests. By day 4 all 5 bunting nestlings in para-
sitized nests were dead. A graph of nestling
mass over time shows a stead\' decline in weight
of host nestlings in parasitized nests (Greene
et al. 1996).

I obsei-ved 57 feeding trips at 2 parasitized
nests. In the 1st nest, the cowbird hatched the
same day as 1 bunting nestling and the da\
before the other bunting nestling. In the 2nd
nest, the cowbird nestling hatched 1 d before
3 bunting nestlings. All observed feeding trips
occurred 1-3 d after hatching. Of 57 feeding
trips observed at 2 parasitized nests, 32 of 46
resulted in only the cowbird being iri\ at 1 nest
O)inoniial test, P = 0.02), and I 1 of 1 1 rc-sulted
in only the cowbird being fed al the 2ik1 lu-st
(binomial test, P < 0.001).

I observed an average of 6.75 (.v = .992)
feeding trips per hour lor (i un|)arasili/.c(l
nests (/( = 87 feeding trips lo IS ncsllings)
where bunting nestlings were 1-3 d old. This
did not differ significantK from tlii- axt-rage
6.14 (.V = T86) feeding trips per hour in 2 par-
asitized nests (n = 36 feeding tii|)s to 5
nestlings) where bunting nestlings were l-.'5 d

old (Mann-Whitney U test, P = 0.39). These
results should be interpreted with caution
since the power of this test is low. There was a
trend toward cowbird nestlings (18.46 per
hour) receiving a larger volume of food per
hour than bunting nestlings (11.64 per hour;
Mann-Whitney U test, P = 0.06).

The relative strength of the provisioning
stimulus provided by bunting nestlings did
differ between parasitized and unparasitized
nests. Lazuli Bunting eggs in the same nest
usually hatch on the same day (Greene et al.
1996). Consequently, the degree of develop-
ment and corresponding height of the gape of
bunting nestlings between 1 and 4 d of age in
unparasitized nests were relatively even.
However, I observed that at eveiy feeding trip
to parasitized nests, the gape of the cowbird
nestling was at least 2.5 cm higher than the
gape of the bunting nestlings. For all 36 ob-
served feeding trips to parasitized nests dur-
ing days 1 and 2, at least 1 bunting nestling
could be seen begging. But after da\ 2 of re-
ceiving less than 20% of the food deli\ered to
the nest, the bunting nestlings in parasitized
nests often did not gape when an adult arrixed
with food. B)' day 4, both bunting nestlings in

1 parasitized nest died of star\ ation and were
found flattened in the bottom of the nest. Two
bunting nestlings in the 2nd parasitized nest
also died of starvation on da\ 4. 1 he third 4-d-
old bunting nestling was found dead on the
ground below the 2nd parasitized nest.

My observations reveal that gaping and
jostling for position by the much larger cow-
bird nestling often mo\e the bunting ni'stlings
aiound inside the nest. Most of these interac-
tions appear to be nonaggressi\e; howexer, on

2 occasions I witnessed what api^eared to be
aggressive head pecking b\ cowbird nestlings.
On 4 separate occasions I witn(>ssed a singU'
3-d-ol(l bunting nestling settle onto tlie back ol
a 4-d-()Id c()wl)ird nestling. In e\cM\ instance,
the cowbiid raised up on its li-gs within 1-3
sec and nio\i'd backwards or to the sick' lor
3-12 sec until the bunting nestling was no
longer touching its back. On 2 occasions this
resulted in the o-d-old bunting nestling lying
on its side perpendicular to llii' lini ol the nest
with its head outside the nest and the ii'st ol
its body diri'ctK on ihi- rim. In both instances
the biuiting lu-stlings raised thi'ii- heads and
fell back into the nest within 3-5 sec. Upon
returning to this nest the next da\, I found 2

19981

N()Ti-:s

287

htiiitiiiL!; iicslliiiiis (li'ad iiisiclr tlic iicsl and llic
3r(l htiiitiiiu; iR'stlintz; Kiiiii on the uioiiiul
(lirctlK ht'Iow tlic nest.

Ill adtlition to mortalit\ Iroiii iiicU'iiifiit
weather, nestling predation, physical aggres-
sion from cowbird chicks, and ectoparasites,
iii\ resnits suggest that another cause of re-
(hiced nesthng sur\i\al in parasitized La/idi
Bunting nests is star\'ation, which resiiUs from
cowbird nesthngs receiving most of the food
deh\c'red to parasitized nests. While this
ap|)ears to be the primar\ factor responsible
liir reduced reproductive success in parasitized
Lazuli liunting nests, my obsen'ations of nest-
ling acti\ ity also re\eal that host \oung may be
iiidirectK ejected from the nest as the cowbird
nestling attempts to maintain its position.

I he relati\c' importance of ejection as a
source of mortalit\ and the abilit\ of cow birds
to eject host species larger than Indigo or
Lazuli Buntings remains unknown! (Dearborn
1996). Gi\en that nestlings of many small host
star\e in parasitized nests (Mayfield 1977,
Pa>ne 1977, Nolan 1978, Marxil and Cruz
1989), ejecting them would seem to do little to
increase cowbird nestling fitness. However,
main host si:)ecies nestlings gain weight nor-
malK (Field sparrow [SpizcUa piisila], (>arey et
al. 1994; Common Crackle [Qiii.scalu.s (luisciila].
Peer and Bollinger 1997; Prothonotai) War-
bler [Pwtonotari citrea]. Petit 1991; Red-winged
Blackbird [A^ehiius phoeniceiis] and Yellow
Warbler [Dciulroica petechia], Weatherhead
1989; Dickcissel [Spiza americana]. Hatch
1983) in parasitized nests, and ejecting them
would likeK increase the fitness of cowbird
nestlings.

Another possible factor influencing ejection
of host \ oung could be nest shape. Nest shape
\aries both widiin and among species. Twent>-
si.\ Lazuli Bunting nests from m\ stud\ site
\aried in depth from 3 to 5.5 cm, averaging
3.5 cm (Greene et al. 1996). A nest depth of
■3-4 cm is t\pical of many cowbird host species;
howexer, there is considerable \ariation in
nest depth of cowbird hosts (Harrison 1975).
Species with shallow nest cups may lose pro-
portionalK more \oung due to ejection than
species with deep nest cups. Gixen the recent
e\ idence in support of cowbird nestling ejec-
tion behavior, I would encourage researchers
to consider this behavior and its potential
impacts on cowbird fitness in future studies of
nest parasitism.

I thank Ale.\ BacKaev, Paul Switzer, Eric
Bollinger, Don Dearborn, and Alexander Cruz
lor rexiewiiig earlier M-rsions of this manu-
script. Mercedes Da\ ison heljied with field-
work, and Erick Greene provided financial
siijiport during m\' research.

Liii.n.vrL HI-: Cited

Carev, M., D.E. Blhhans. ano D.A. Nelson. 1994. Fieid
Sparrow (Spizella pusilla). In: A. Poole and E Gill,
editors. Tlie l)ird.s of NOrtli Anieriea, No. 10.3. Aead-
iMii\ of Natural Seiences, i'liiladelphia, PA, and Amer-
ican Ornithologists' Union. Washington, DC.

Dearborn, D.C. 199B. Video doenmentation of a Brown-
headed Cowbird nestling ejecting an Indigo Bnnting
nestling from the nest. Condor 98:64.5-649.

. 1997. Nestling behavior oi a brood parasite: food

aetjiiisition and predation risk of Brown-headed Cow-
birds. I npnblished doctoral dissertation, Uni\ersit\'
of Missoini-(!olnmbia.

Fhiedmann, 11. 1929. The cowbirds; a stud\ in the biolog)
of social parasitism. C. Thomas, .Spiingfield, IL.

Greene, E., V.R. NUehter, and W.B. D.uison. 1996.
Lazuli Bnnting (Passerina amoena). In: A. Poole and
E Gill, editors. The Birds of North America, No. 2.32.
Academy of .Natural Sciences, Philadelphia, PA, and
American Ornithologists' Union, W;ishington, DC.

Harrison, H.H. 1975. A field guide to birds' nests.
Houghton Mifflin Co., New York.

Hatch, S.A. 1983. Ncsding growth relationships of Brown-
headed Cowbirds and i:)ickcissels. Wilson Bulletin
95:669-671.

Leon.\rd, M., and a. Horn. 1996. Proxisioning niles in
tree swallows. Beha\ioral Ecolog\' and SociobiologN'
38:341-347.

Lowther, PE. 1993. Brown-headed Cowbird iMi)lnthrtis
(iter). In: A. Poole and E Gill, editors. The Birds of
North .\merica, .No. 47. Academ\' of Natural Sciences,
iliilatlelphia. P\. and American Ornithologists Union,
Washington, DC.

Marx n„ R.E.. and A. Crlz. 1989. Impact of Brown-headed
Cowbird parasitism on the reproductive success of
the Solitarx- V'ireo. Auk 106:476-480.

M AV, R.M., AND S.K. RoRlNSON. 1985. Population dxuamics
of avian brood parasitism, .\nierican .Natmalist 126:
475-494.

Mayfield, H.E. 1977. Browu-headed Cowbird: agent of
extermination':' American Birds 31:107-1 13.

Nice, M.M. 19.53. The question of ten-dax incubation
periods. Wilson Bulletin 65:81-93.

Nolan, V., Jr. 1978. The ecolog>- and behavior of the
Prairie W'arbler Denclroica discolor. Ornithological
Monographs No. 26. .\merican Ornithologists' Union,
Washington, DC.

NoRRls, R.T. 1947. The cowbirds of Preston Erith. Wilson
Bulletin .59:8.3-103.

Orte(;a, C.P, and A. Criz. 1991. A comparatixe study of
coxxbird parasitism in Yellow-headed Blackbirds and
Red-xxinged Blackbirds. .-Vuk 108:16-24.

Payne, R.B. 1977. The ecologx of brood parasitism in birds.
Annual Rexiexv of Ecologx and Systematics 8:1-28.

Peer, B.D., and E.K. Bollinger. 1997. Common Crackle
{Qtiiscahis qulscula). In: A. Poole and E Gill, editors,
The Birds of North America, No. 271. Academx of

288

Great Basin Naturalist

[Volume 58

Natural Scientt's, Philadi'lpliia, FA, ami AiiKiicaii
Ornithologists' Union, Washington, DC.

Petit, L.J. 199L Adaptive tolerance of cowbird parasitism
by Prothonotar\ Warblers: a consequence of nest-
site hniitation? Animal Beha\ior 4L425 — 132.

Scott, T.W'. 1979. Crowth and age determination ol nest-
ling Brown-headed Cow birds. Wilson Biilli'tin 9L
464-466.

Smith, H.C, .\nd R. Montcomkkif. 199L Nesding Amer-
ican Robins compete with siblings b> begging. Behav-
ioral Ecology' and Sociobiology 29:307-312.

Te.vitier, K.L. 1992. An experimental stud\' of competi-
tion for food between male and female nestings of
the Red-wing Blackbird. Behaxioral Ecology and
Sociobiology 31:81-87.

r\\OME\, A.C. 1945. The bird population of an elni-niaple
forest with special reference to aspection, territorial-
ism, and coactions. Ecological Monographs 1.5:
173-205.

Weatherhe.ad, RJ. 1989. Se.x ratios, host-specific repro-
dncti\e success, and impact of Brown-headed Cow-
birds. Auk 106:358-366.

Zah, J.H. 1996. Biostatistical analysis. Prentice Hall. I pper
Saddle River, NJ.

Received 10 Fchnmnj 1997
Accepted 27 September 1997

Civat liasiii Naturalist 58(3), © 1998, pp. 289-291

OBSER\ATI()\S OF BLACK-RTLLED MAGPIES (PICA PICA)
GROOMING EEIUL HORSES [EQUUS CABALLUS)

Michael C. AsliK-y'
Kit/ uonls: Bhick-hillcd M(ini>ics. Pica pica, /c/v// /ioc.sr.v, <iri)<)iitin'^ habits.

On 4 March 1995 I wei.s oh.scnini; Icral
hor.scs {E(jiiii.s cahalhis) in thr soiitlitvi.st .sec-
tion of the Granite Range in Ne\a(la (hititnde
4()°47'19" North, longitude 119°18'13" West)
ilMg. 1), when I witnessed an interaction be-
tween a Black-Billed Magpie {Pica pica) and 2
of ni\ stiid\ animals. The magpie alighted on
the hack of the 1st horse and mo\ed around
the animals back. The magpie appeared to be
scanning each new section of the horse's back
as it moved, occasionalK making pecking move-
ments with its head, presnniablx remo\'ing
ectoparasites from the animal. After about 3
min, the magpie left the 1st horse and landed
on the back of the 2nd animal. It repeated its
searching and picking beha\ ior, this time mov-
ing onto the horse s neck and searching exten-
si\el\ through its mane. After 5 min on the
2nd horse, the magpie returned to the 1st and
searched its mane for more than 1 min. Nei-
ther horse attempted to displace the magpie
and both remained quiet throughout the visi-
tations, suggesting familiarity with this behav-
ior. I was able to closeK observe the magpie
behaxior with a Kawa 22-6()X spotting scope
from ~2() m.

On 17 Febriiar\ 1996 I saw a repeat of this
beha\ior with 2 magpies and 2 different feral
horses. This episode occurred appro.\imatel\- 2
km east-southeast of the 1st observation but
within the same \'alle\'. A magpie landed on
top of the withers of the 1st horse and moved
about its back for 3 min, occasionalK picking
at the liorse s back.

During the same period a 2nd magpie flew
to a nearb\- sagebrush {Artemisia tridcntata)
and appeared to be watching the behavior of
the 1st bird. The 2nd magpie then flew to the
back of a 2nd horse and proceeded to search

and pick for appro.ximately 3 min. During the
grooming i)out this magpie climbed into the
mane of the horse, again without any adverse
response. The wind was \ariable, 10-15 kph,
and stronger gusts occasionally caused the 2nd
magpie to struggle to maintain its footing. In
one instance the horse twitched, dislodging
the magpie.

I next obsen-ed 2 magpies grooming a \ear-
ling feral horse on 12 April 1997 in the Gran-
ite Basin, approximately 7 km south-southwest
of the previous 2 sightings. This encounter
lasted slightly more than 10 min. One of the
magpies groomed the horse's rump, back, and
dorsal area of its neck up to the base of its
skull. The 2nd magpie clung to and groomed
the ventral surface of the animals neck for
more than 1 min, moved to the inner aspect of
the right foreleg at the hock for 4 min, and
then briefl)' returned to grooming the under-
side of the horse s neck. Although there were
periods when one or the other of the birds was
not on the horse, there were 2 magpies
grooming the animal simultaneously for more
than 5 min.

The regularitx and extent of this behav ior is
impossible to determine at this time. In more
than 50 trips to this area, I have witnessed
only these 3 incidents involving magpies and
feral horses. The distances between observa-
tions at the Granite Ranch site and between
Granite Ranch and Granite Basin can lead one
to believe that magpies in this area search for
horses to groom rather than wait at an estab-
lished feeding station as descril:)ed by Isenhart
and DeSante (1985) for Scrub Ja>s (Aphelo-
coma coendescens) cleaning C'olumbian black-
tailed deer iOdocoiletis hemionus colwnhiamui).
That conclusion, however, cannot be supported

'BioloRN Dcpartnipnt, L'niversihof Nevad;i. Reno. N\' 89.S57

289

290

Great Basin Natl ralisi'

[Volume 58

FiU, 1. Locations (,rKnKHiiiimcvcnts;(l)(;raniU' Haucli. 4 \laivli 1995; (2) ( i.aiiitc Kaiidi, I, I'rl.nian 199(S; (3) Cninitt-
Basin, 12 April 1997. Kniai^c'd (roni l.S. ( ;colo-j;ical Snnvy 1 : lOO.OOO ( Uiiacli. \\, map.

by the small number of obsenaticms and laek
of indivichial ideiitifieation of the birds imoKcd.
On 3 ()eeasi(ms I \vd\c seen nia.upies in the
vieinity of leral horses in e\'en more remote
sites in the (iranite Halite; however, I saw no
^roominj!;.

\hii!;pies exhibit a \ariety of opportunistie
loraKin.U praetiees inehidint^ seaxenpnu;, prc\ -
inii; on nests ((irooni HJ^J.'i ranipnsli and
AnthonN UJ93), pre\in<j; on small nianinials
(Conlden 1973), and Uroomin.U larUc licibi-
vores (Dixon 1944, Linsdale 1946, l.insdale
and Tomieh 1953, Massei and Geiiov 1995).

Ma<j;pies are reputed to probe sores on the
backs oi'domestie and wild animals diat are in
poor plnsieal condilion (Hcndire 1S95). .\11 ol
the horses 1 obserxed beinu uroomed b\ maii-
pies were in exeelleut eondition. Beeause I
\ iewcd the belia\ iois iloseK. Ironi <2() m with
a 22-()0.\ spoltiuii seope. I am lonlidi'nt that
<4n)oniin<i took plaei'. 1 suspict the matipies
weic remoxiu.U eetoparasitt's I'rom the animals,
not probinu sores. Tieks d'arasitilbrmes: Mela-
s(i'j;niata) are abundant nianunalian t'etojiara-
sites in the ( iranite Kaniie and aic likeK objeets
(jl'the mat;i)ies" beluiN iors.

1998]

NOTKS

291

rlicsc ()l)s('i\ alioiis add lo tlii' iiiiiiiluM' ol
appaiciith iiiiiliialistic iiiti'iactious hcfwccii
forxids and laruc licrhix orrs. Iliis t".\ten.si\ (,■
it'lationship incluck'S (1) Black-hilled Ma.upies
(Liiisdalc 1946). Vc-llow -billed Mat^pies {Pica
nuttuli) (Linsdalc and Ibmicli 1953), and Cali-
lornia Scrub Ja\s {Aphelocoina californicu)
(Dixon 1944) intcractinii; witli uuilc deer iOdo-
coili'ns lu'inioiuis): (2) Black-billed Magpies
(Linsdale 194(-)) willi elk {Cervus canadensis);

(3) Florida Scrub Ja\s [Aphelocoma coendes-
cens) with white-tailed deer (Odocoileus vir-
ginianus) (Fitzpatrick and \\boHenden 1996);

(4) Scrub Ja\s {Aphcloconia cocndcsccns) with
Columbian black-tailed deer {Odocoileus heuii-
onus colwnhianus) (Isenhart and DeSante
1985); (5) Conunon Crows {Corvus hrachij-
rht/nclios) with cattle {Bos taiinis) (Kilhani
19S2); and (6) C^onunon Crows {Coitus hrachy-
rhynchos) (Kilhani 1982), Florida Scrub Ja\s
[Aphelocoma coendescens) (Baber and Morris
1980), Black-billed Magpies, and Carrion
Crows (Corvus corone comix) with feral hogs
{Sus scrofa) (Massei and Genov 1995).

My thanks to E. Cra\' and S.H. Jenkins For
review and comments, and to the Bureau of
Land Management for supporting ni\ feral
horse research.

Bl NDllil , CM. ISUl. Lilc liistnijcs ol Noitli AiiuTJcaii
liiids. Siiiitlisoiiiaii Institution, Wasliinj^ton, DC.

I)i\()\, J.C. 1U44. Caliloniia ScrnI) Jay picks ticks IVoni
imilc dcfi". Condor 46:204.

!• rr/.i'.vnucK. (S,.\\.. wu C.E. \\'(J()1.i-i:m)i;\. UW(i. I'lorida
.Sc'nil)-Ja\ forages on liack ol uliitc-lailcd (k'cr. Con-
ck)r 98:422-123.

(ioi'I.UKN. L.L. 1975. Magpie kills ground s(|uiir(l. .\uk
92:606.

(;iU)OM, D.W. 1993. Magpie Pica pica predation on lilaek-
hird Tardus vwrula nests in iirhan areas. Bird .Stuck
4():.55-62.

isi:\H.\RT, KK., AM) D.K Dk.Sami,. 198.5. ()i)ser\ati()ns ol
Scrul) Ja\s cleaning ectoparasites Irom Mack-lailcd
deer. Condor 87:14.5-147.

K.ll,HA.Vl, L. 1982. (Meaning/feeding synihioses of Common
Crows witli cattle and feral liogs. [onrnal of Field
OrnitI)olog>- 53:275-276.

LiNSOAi.K, J..\l. 1946. American Magpie yl'ica pica). Pages
133-154 in A.C. Bent, editor. Life liistories of North
American jays, crows, and titmice. U.S. National
Museum Bulletin 191.

Ll.NSDALE, J..M., AM) PQ. ToNIK II. 19.53. A herd ol mule
deer. Universit>' of California Press, Berkelex.

.\1.\SSEI, G., A.ND R Ceno\. 1995. Obserxations of Black-
hilled Magpies [Pica pica) and Carrion Crow [Corvus
cnronc comix) grooming wild hoar (.Si/.v scrofa). Join^-
nal of Zoology London 236:338-341.

Pampush, G.J., AND B.C. Anthony. 1993. Nest success,
habitat utilization, and nest-site selection of Long-
hilled Curlews in the Columbia Basin, Oregon. Con-
dor 95:957-967.

Received 18 June 1997
Accepted 27 September 1997

Literature Cited

lUliKH, D.W., .\ND J.G. MoBRIs. 1980. Florida Scrub jaxs
foraging from feral hogs. Auk 97:202.

Great Basin Naturalist 58(3), © 1998, pp. 292-293

FISH PREDATION ON GIANT WATER BUG (HETEROPTERA:
BELOSTOMATIDAE) EGGS IN AN ARIZONA STREAM

Hohrrt L. Smith' and (,'liris Ilorton-
Key words: Ahcdus lierherti, hwodiii^. c<j.fS. i^'cddlion. (Kjitatic in.'icci^Jisli did. stomacli citntcnts.

We caught 3 browii trout {Sahno truttti) in
the White Mountains of east central Arizona
just after daxbreak on the morning of 20 April
1997. The fish were taken in the South Fork of
the Little Colorado River, elevation ca 2350 m,
ca 10 km southeast of Springerville, Arizona.
The 3 fish ranged in size from 18 to 20 cm TL.
The brown or German trout, a European
species, has been widely distributed in the
United States since its introduction to North
America in the late 19th century (Carlander
1969). This species was introduced to the
White Mountains of Arizona sometime in the
1920s (Miller 1972). Brown trout are pro-
duced in hatcheries and released in Arizona
streams including the Little Colorado River to
pro\ ide a sports fishery.

Pooled stomach contents oi the 3 iish con-
tained 27 Trichoptera (Helicopsychidae and
Limnephilidae) lanae in their cases, 5 mayfly
nymphs (Baetidae), 3 Plecoptera (nymphs and
adults), 2 a(|uatic Heteroptera (a naucorid and
an early instar belostomatid), plus a variety of
terrestrial insects. In addition to these items,
one of the trout stomachs contained 10 giant
water bug {Ahcdus Iwrhcrti Hidalgo) eggs. The
eggs, white in color with tan apices, were in
good condition and contained nmcilage on
their distal ends. Prom this evidence we infer
that the ova had recently been laid and, soon
after their deposition, consumed by the fish.
Brown trout are able to feed at starlight (10 '
foot Lamberts) intensities (Bobinson 1978);
thus, the eggs were probabh' eaten during the
night.

Giant water bugs, aquatic Heteroptera in
the famih Belostoniatidae, are lonnd in tropical
and temperate freshwater habitats through-
out most of the world. In members of the giant

water bug subfamily Belostomatinae, females
glue their eggs to the backs of their mates, and
the males then acti\el\ brood the eggs in a
variet}' of ways (Smith 1997). Most belostoma-
tines inhabit lentic habitats, but species in the
New World genus Abedus are stream dwellers
(Menke 1960). Abedus herJ)Ciii occms in Ari-
zona streams at elevations of ca 1000-3000 m.
Males of this species brood their eggs by
exposing them to the atmosphere while resting
on vegetation or rocks such that the bug is
submersed with the tops of the eggs exposed
to the air. When below the surface of the w ater,
encumbered A. herherti males aerate their eggs
by "brood-pumping, " i.e., rocking longitudi-
nally about once per second to circulate water
over the eggs for enibnonic respiration (Smith
1976).

When Abedus spp. eggs are first laid, the\-
are white in color with tan caps. As the eggs
develop, they take on a grayish color and
enlarge. Near hatching time the dorsal portion
of the chorion becomes ash gray. In all stages
of de\el()pment, eggs are highb' conspicuous
against the male s dark brown back, (iiant water
bug ova are among the largest insect eggs.
Fully developed Abedus herberti eggs ctm reach
6 nun in length and 2 nun in width. Adult
Abedus herberti bugs range from 24.5 to 10
mm in length and 12.5 to 22 nun wide (Menke
1960). Thus, the size of adult bugs substau-
tialK- exceeded the gape of thi' small troiil wi"
caught.

Piior to tills ()bsi'r\ atiou tlicrt' liavc been
no reports ol prcdatiou or parasitism ol au\
kind on giant walei' bug t'ggs, nor haxc tlusi-
huge insect eggs e\er been noted in flu' stom-
ach contents ol fish. It seems possibk' that
fisheries l)iok)gists w ho routiucK sample sports

' Oc'parliiuMit (il KntdiiioliiKy. L iiivcrsity of Arizoiui. Tiicsoii, AZ 8.5721 .

^School of Kciicwiibic' Natural Hi'sourccs, University of Arizona, Tucson. A/. 8.5721.

292

1998]

Notes

293

lisli stomach contents mi.^ht not lia\c rccoy-
nizcd uiant water bug eggs for w hat the\ are.

Il()\\e\er, it is not surprising that these con-
spicuous eggs attached to actixi'K l)r()0{hng
giant water hugs would attract the interest ol
foraging fisli who might regularK' snatch eggs
from encinnhered male bugs backs. If this is
the case, fish could be significant predators of
Ahcdus spp. eggs throughout the range of the
genus from southern Utah through Arizona
and Mexico to Central America. It is also pos-
sible that the eggs were inadvertentK ingested
when the small fish attempted to eat a \-er\-
large bug. The authors would be grateful for
aii\ additional accounts of giant water bug
eggs found in fish stomachs.

Lii'KHAii HH Cited

C.\KL\.\Dl£K, K.D. 1969. Handbook of fresliwatcr fi.shen
biolog). \blunie 1. Iowa State Universit\' Press, .\jiies.
752 pp.

-MlAKi:, .\..S. 19{i(). A taxoiioiiiic stiuK ol liie jieiiiis
Alwdus Stal (llemiptera, Belosloiiiatidae). University
ofCiJifbrnia Publications in Entoinolog\- 16:393-440.

MiLLl£K, R.R. 1972. Classification of the native trouts of
Arizona with the description of a new species, Salmo
apache. Copeia 1972;4() 1-422.

lioBlNSON, FW. 1978. Feeding In brown trout {Salmo trutta)
and Arizona trout (Sahno apache) at various light lev-
els. Unpublished masters thesis, Uni\ersit\' of Ari-
zona, Tucson.

S\irrn, R.L. 1976. Male brooding behavior of the water
bug A/;('f/».v herheiii (Heteroptcra: Belostoinatidae).
■\inials of the Kntoniologieal Societx of Aineriea 69:
740-747.

. 1997. E\<)lution of paternal care in the giant water

bugs (Heteroptera: Belostomatidae). In: J.C. Choe
and B.J. Crespi, editors. The e\ oliition of social be-
liaxior in insixts and arachnids. Cainbiidge Uni\ersit\'
Press.

Received 28 Au<iust 1997
Accepted 27 September 1997

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Mack, CD., and L.D. Flake. 1980. Habitat relation-
ships of waterfowl broods on South Dakota
stock ponds, journal of Wildlife Management
44:695-700.

Sousa, W.P 1985. Disturbance and patch dynamics
on rocky intertidal shores. Pages 101-124 in
S.T.A. Pickett and PS. White, editors. The ecolo-
gy of natural disturbance and patch dynamics.
Academic Press, New York.

Coulson, R.N., and J. A. Witter. 1984. Forest ento-
mology: ecology and management. John W'iley
and Sons, Inc., New York. 669 pp.

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(ISSN 001 7-3614)

GREAT BASIN NATURALIST voi se no 3 juiy 1998

CONTENTS

Articles

Gap analysis of the vegetation of the Intermountain Semi-Desert ecoregion ....

David M. Stoms, Frank W. Davis, Kenneth L. Driese,

Kelly M. Cassidy, and Michael E Murray 199

Natural histor)' of a saline mound ecosystem Robert R. Blank,

James A. Young, James D. Trent, and Debra E. Palmcjuist 217

Winter macroinvertebrate communities in two montane Wyoming streams

Christopher M. Pennuto, Frank deNoyelles, Jr., Mark A. Conrad,

Frank A. Vertucci, and Sharon L. Dewey 231

Range of the Brown-headed Cowbird in Colorado: past and present

Jameson E Chace and Alexander Cruz 245

Chemical and biological characteristics of desert rock pools in intermittent

streams of Capitol Reef National Park, Utah Jill S. Baron,

Toben LaFrancois, and Boris C. Kondratieff 250

Survivorship and cause-specific mortality in five populations of mule deer

Vernon C. Bleich and Timothy J. Taylor 265

Persistence of subalpine forest-meadow ccotones in the Gunnison Basin, Colorado

Andrew J. Schauer, Brian K. Wade, and John B. Sowcll 273

Comparison of the epiproct structure of two closely related species, Sweltsa

fidelis (Banks) and S. revelstoka (Jewett) (Plecoptera: Chloroperlidae)

Jennifer K. Delk, Mar\' Jane Kilgore, and Bill R Stark 282

Notes

Starvation and nestling ejection as sources of mortalit> in parasitized Lazuli

Bunting nests William B. Davison 285

Observations of Black-billed Magpies {Pica pica) grooming feral horses {Faiuu.s

cabalhis) Michael C. Ashle> 289

Fish predation on giant water bug (Heteroptera: Belostomatidae) eggs in an

Arizona stream Robert L. Smith and Chris Horton 292

H E

GREAT BASIN

NATURALIST

VOLUME 58 N^ 4 — OCTOBER 1998

ML. BEAN LIFE SCIENCE MUSEUM

BRIGHAM YOUNG UNIVERSITY

GREAT BASIN NATURALIST

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E-mail: richard_baumann@byu.edu

Assistant Editor

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Associate Editors

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Department of Environmental Technology

Utah Valley State College

Orem, UT 84058

Bruce D. Eshelman

Department of Biological Sciences, University of

Wisconsin- Whitewater, Whitewater, WI 53190

Jeffrey R. Johansen

Department of Biology, John Carroll University

University Heights, OH 44118

Boris C. Kondratieff

Department of Entomology', Colorado State

University, Fort Collins, CO 80523

Paul C. Marsh

Center for Environmental Studies, Arizona

State University, Tempe, AZ 85287

Jerry H. Scrivner
Department of Biology
Ricks College
Rexburg, ID 83460-1100

Stanley D. Smith
Department of Biology
University of Nevada-Las Vegas
Las Vegas, NV 89154-4004

Robert C. Whitmore

Division of Forestry, Box 6125, West Virginia

University, Morgantown, WV 26506-6125

Editorial Board. Richard A. Heckmann, Chair, Zoologv'; Jerran T Flinders, Botan\' and Range Science;
Duke S. Rogers, Zoology; Bmce A. Roundy, Botany and Range Science; Richard R. Tolman, Zoology; Larr\' L.
St. Clair, Botany and Range Science; H. Duane Smith, Monte L. Bean Life Science Museum. All are at
Briglram Young University. Ex Officio Editorial Board members include Steven L. Taylor, College of Biolog)'
and Agriculture; and Richard W. Baumann, Editor, Great Basin Naturalist.

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in western North America are accepted for publication.

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C^opyrij^lit © 1998 l)y Brij^liaiii Yoiinj^ University
Oilicial publication date: 12 October 1998

ISSN 0017-3614
10-98 750 27394

The Great Basin Naturalist

1^ hiisiii.i) M l'H()\(), I I \ii. in
ML. Bi-:an Lifk Science Museum

Biiiciiwi Yoi'xc U\'i\i:i{siTY

ISSN 0017-3614

Volume 58

31 October 1998

No. 4

Crrat Basin Xatinalist .58(4), © 1998. pp. 295-;5I 1

ALGAL COMPOSITION OF MICROBIOTIC CRUSTS FROM THE
CENTRAL DESERT OF BAJA CALIFORNIA, MEXICO

Nalt'iie H. FleditiuT>. Jeffrey H. jolianscn'. aiitl William II, Claik^

Ah.stract. — A total of B(i al<4al specie.s representing .32 genera were reeoxcred from soils ol 10 sites in the (,'ata\ina
region of the Central Desert of Baja California, Mexico. The most conmion species encountered were the cyanophytes
Nnstoc commune and Schizothrix calcicola, the chloroph\te Mi/rmcria asliomatica, antl the diatoms Hantzschia
(imphioxys, Hantzschia ampliyoxys f capiiata, Luticola cohnii. Liiticola Diiiticii. and Fiimiiliiria horcali.s \ar sciihiris. Nine
sjieeies not found in any pre\ioiis studies of North American desert soils were present in our stud\ sites, including .'3
ta\a new to science: Cylindrocysti.s brehissanii van cleserfi, var nov.; Elakatothrix ohtusuta, sj). uon.; and Fasciciilocliloris
mexicana, sp. no\'. Attempts to correlate species composition with soil chemical and physical parameters were unsuc-
cessfril apart from a pH effect on c>an()l)acterial distribution. ()\erall composition of the soil algal comniunit\- in the
Cata\ifia region is distinct from other desert sites we ha\"e studied, although some cosmopolitan desert soil taxa were
present.

Key words: al<iae, soil; Mexico, Baja California; Central Desert; Catavina; cnjpto<iamic crusts; C\lindroc\ stis hrehis-
sonii var deserti: Elakatothri.x ohtusata; Fasciculochloris mexicana; microbiotic crusts.

Microbiotic crusts, also called crypt(),u;ainic
crusts, cr>'ptobiotic crusts, and niicroplntic
crusts, are common in man\^ arid and scmiarid
areas in the western United States (St. Clair
and Johansen 1993). The\ consist of lichens,
mosses, algae, and fungi, wliieli (orni water-
staljle surface aggregates that ha\e been demon-
strated in some regions to be important in sta-
bilizing soil and pre\euting erosion (Harper
and Nhirble 1990, Johansen 1993, Williams et
al. 1995, \\'illiams, Dobrowolski, and West
1995). Furthermore, man\ of the free-li\ ing and

lichenized c\'anobacteria fix atmospheric nitro-
gen and can be significant contributors to
desert nitrogen budgets (Rychert and Skujins
1974, Evans and Ehleringer 1993, Belnap
1996). Crusts are susceptible to damage b\' li\ e-
stock, backpackers, and off-road vehicular traf-
fic, which disrupt the crust, compact the soil,
and if fre(juent enough, kill algal, lichen, and
moss components of the crust (Kleiner and
Harper 1972, Anderson et al. 1982). Rangefire
can also seriousK' impact the crust connnunih'
(Johansen et al' 1982, 1984, 1993). Natural

iDepartnient of Biologv. Juhii Canoll L niversih, 2()7(M) Nortli Park Blvd., I niversity Heii;hts, OH tU IS.

20niia J. Siiiitli Museum of Naluial lliston.. .^llx-rtson CloIIege of Idalio, 21 12 C:k-vi-lancl Blvd., Caldwell, ID 8.360.5-44.32.

295

296

Great Basix Nati i^m.ist

[Nblunie 58

rec()\'en' from disturbance' can take Ironi a lew
to iiian\ years (Anderson et al. 1982, Joluinseii
et ul. 1984, 1993, Callison et al. 1985).

Interest in the algal component of these
conmiunities has increased in recent years.
EarK in\estigators of these algae were in-
trigued by the occurrence of a group of organ-
isms generally thought to be aquatic in such
an extremely arid environment. Floristic work
has demonstiated the presence of a number of
algal genera, some of which also occur in
aquatic habitats, and many of which are con-
fined to terrestrial ecosystems. Most fresh-
water divisions are represented: Cyanophyta,
Chlorophyta, Eustigmatophyta, Chr\sophyta,
Xanthophyta, Bacillariophyta, and Eugleno-
phyta. In previously published work re-
searchers tended to focus on 1 or 2 taxonomic
divisions. The cyanobacteria are prol)ably the
best studied group because identifications can
be made based on moiphot\'pes in moistened
soils, although there is considerable disparity
between cyanobacterial floras based on mi.xed
cultures and those based on unialgal isolates.
Diatoms are usually superficially treated, al-
though Rushforth and researchers trained in his
laboratory have foiuid considerable diversity
in this group by direct preparation of soil dia-
toms (Anderson and Rushforth 1976, Johansen
et al. 1981, 1984, Ashley et al. 1985, Johansen
and St. Cvlair 1986). Green algae, although
abundant and ubicjuitous, are much less thor-
oughly studied due to the necessity of work-
ing with unialgal isolates in which details of
life history (i.e., zoospore niorphologx, color
changes with senescence, etc.) are recjuired
for correct placement in genus and species.
Johansen et al. (1993) made some effort to
identify green algal isolates and demonstrated
the potential di\ersit\ of coccoid chloroph) tes
in soils.

Most recent papers dealing with taxononu
and distribution of desert soil algae studx (lie
sennarid shrub steppe and cool deserts in tlie
Great Basin and ("olorado Plateau proxinces
(see Johansen 1993 lor a rc\ iew ol (licsc
papers). .Most work on soil algae of liol deseits
was done in (lie earl\ 196()s. 'rliesc studies
include boili llic Soiioiaii ((.aincron 19()(),
1964, elc.j and Mojave (l)urrell 1962, .Shields
and Drouet 1962, Hunt and Durrell 1966)
deserts. lb our knowledge, (he (,'iuliuahuan
Desert soil algal flora has n()( been s(u(li('(l,
although a single icpoit of soil algal dcnsKy

doi's exist (Cameron 1969). All work on hot
deserts emphasizes the cxanobacterial compo-
nent of the soil community.

The objectives of the present stud\' were
twofold. First, we wished to carehilK charac-
terize the algal conmumity from the (AMitral
Desert of Baja California, Mexico, a hot desert
region previously unstudied with regard to its
soil algal flora. Second, we wished to test for
correlations between algal composition and
soil chemical and physical properties in sites
with highly similar climate. Although soil
chemistr) has been considered important in
determining soil algal distribution (Starks et
al. 1981), correlations between taxa in desert
soils and soil chemistiy have not been made.

Materials and Methods

Study Area

Ten study sites were established in the
Cataviiia area of the Central Desert of Baja
California, Mexico (Fig. 1), a mid-peninsular
location 9 km northwest of Rancho Santa lues
(28°46'N, 114°46'W, 550 m elevation). The geol-
ogy is dominated by weathered Cretaceous
granite (tonalite) of the Jaraguay block (Grastil
et al. 1975), the decomposition ol which forms
a coarse, sandy-textured soil (lilom and (^laik
1984). Mean annual precipitation has been re-
ported to range from 46 mm (Blom and ('lark
1984) to 101.7 mm (C;arcia 1981). Mean aimual
temperature is 18-19°C, with a smmner mean
of 25.8°C, a winter mean of 13.2°C (Hastings
1964, Hastings and lluin[ihre\ 1969, (Garcia
1981), and occasional freezing temperatures.
The \ascular plant conununit\ is dominati'd
1)\ Larrca tridcntata (Sesse and Moc.) C>o\iIle
and Am]>r<>si(i clwnopodifolid (Benth.) Paxne,
with spi'cies of Opitiilia being the most c-om-
mon cacti. At each of the 10 sites, wc recorded
presence of all [K-reimial \ascular plant species
adjacent (o (he collection site (Table I). Micro-
l)io(ic ciusts formed significant coxcr in iiiter-
shrub/intercacti spaces (JMgs. 2, '.\). The 10 sites
will be referred (o as Si(es 1-10 in (his paper.
They correspond (o W'.ll. Clark field collec-
(ioii numbers 9.573-9582. Specilic locaOous
ioi' each sample si((' arc as lollow s:

Sid- 1,29°47'04.2".\, 114 46' 11.1 "W;
Si(e 2, 29°46'57.3"N, 114°46'12.4"\\';
Si(e 3, 29°47'()7.8"N, 1 14°46'04.9"W:
Si(e 4. 29"47'10.5"N, 1 14^46'I0..5"\\■;
Site 5, 29 47'17.7"\, 1 14"46'16.2"W;

1998]

MiCHOBIOTIC ClU'STS Ol" H\|\ C\I.IFOR\l\

297

,,/?'i ^~'i ^:'^f'' '"■•"'' '" ^-y-' <-'^ilitonua, Mexico; 1, general topogniplix and vegetation: 2, nuen.hiotie enist at Site
II): .i, detail of algal crust, raised b>' slight disturbance (scale = 12 cm).

Site 6, 29°47'08.7"X, 114°46'29.2"\V;
Site 7, 29°47'09.0"N, 114°46'27.9"\vi
Site 8, 29°46'44.4"N, 114°46'03.9"\vi
Site 9, 29°46'47.8"N, 114°46'04.8'%V;
Site 10, 29°47'03.9"N, 114°46'08.4"\V.

Sample Collection

Sample areas, all within a 2-km area, were
chosen to represent various soil t\pes and habi-
tats present. We obtained the precise location
of each site with a Sony PYXIS IPS-760 global

298

Grkat Basin Natiir.\ijst

[Volume 58

r\i;li 1,

'trcmiial \

cistiil.n^ 1

)l.nit spccj

cs pii'scnt ill

•acl

oi'

llic 10 (iatavina sites.

Sitc-s

Species

1

2

3 4 5 6

7

S

9

10

Ambrosia chenopodijolia (Beiitli.) Pa\ne
Ambrosia diimosa (Gra\) Pa\ iie
Atriplcx pohjcarpa (Torn) S. Wats.
Ceraloidcs lanala (Piirsh) Howell
Enci'lia calijornica Niitt.
Eriofioiiuin fasinilattiin Beiitli.
Larrea tridi-ntata (DC.) Gov.
Lijcium califoniictiin Niitt. ex Gray
Opiinfia cliolla Weber
Opiititia ^aiidcri (Wolf) Rehinan 6c Finkava
Opimtia inolesta Brandegee
Prosopis glandtdosa

var torreijana (L. Benson) Johnston
Simmondsia chiiwnsis (Link) Sclineider
Solanwn hindsiamim Benth.
Viguiera Uiciniata A. Gray
Viscainoa '^cnicidata (Kell.) Greene

X
X

X

X
X

X

X
X

X

X

X

X

X

X

X

positioning system. Vascular plant cover and
percent visible coverage by microljiotic crust
were noted for each plot and recorded photo-
graphically. Composite crust samples consist-
ing of 10 cores (top 3 cm) were taken in a 2 x
2-m area at each site. Additional samples for
soil chemistn' analysis were collected from the
center of each plot. Samples were drv when
collected (29-30 April 1995), and we trans-
ported them to the laboratorx within 1 \vk of
collection, where they were stored under
refrigeration initil analysis.

Cliaractcrization of
Non-diatom Algae

Composite samples were crushed and
mixed to produce a homogenous sample. A 1-
g alic^not was removed and added to 99 ml ol a
0.7% saline solution (as an osmotic protectant)
for a lO- dilution ol the original sample.
Ali(|ti()ls ol 0.1 or 0.2 ml wfre spicad in tripli-
cate on agar solidilied /-<S medium ((^aruiieliael
1980) lor (luanlilalion of (Aanophvta and on
Bold's basal medium (liB.Vl,' liold and Wynne
1978) for (|uanfilati()n ol non-diatom eukaiyolic
algae. (>'iilliu(s were allowed to dry overnight
belore in\ cision, sealed witli jiaralihii, and
incnbaled in constant light at 2()-23"( ,' until
good growth had been obtained (3-6 \\k). We
then eoiniled the nuinbci ol coloin-lorming
iniits on each plate, f'oi" identiliealion ol (Aan-
opIiNla, wet mounts prepaicd directly Ironi
indi\i(lnal isolates on /-S plates were exam-
ined using an OKinpns bll-2 plioloniic lo-

scope with Nomarski DIG optics and pho-
tographed using Kodak FKL-135 film, identi-
fication was made on the basis of cell and
colony morphology using standard authorita-
tive references (Geitler 1930-32, Desikacharx
1959, Kantz and Bold 1909). For identification
of non-diatom eukar>()tic algae, indi\idual iso-
lates were picked into 5 ml litjuid B13M and
incubated 2-4 wk imtil good grow th had been
obtained. Identification was made on the basis
of life history and morphological criteria using
standard authoritative references (Komarek and
Fott 1983, Ettl and Gartner 1995). Because
man\' c\anoph\ tes grow poorh on artilicial
media, additional identilieation of e>anoph\ tes
was made directK lioni wet mounts of wetted
soil samples incubated 48-72 h in the light.

We prepared t> pe mafi'iials in 2 wa\s.
II()lot\pe material was prei^arixl b\ liltering a
xoung, healtin culture onto glass liber lilti-rs
that had bei'u ashed and subse(|nentl\ han-
dled with lorceps to niininuA' the possibilitx
ol eukaiAotie HNA contamination. The lilttTs
wcic allowed to air (h\. placed in glassine
envelopes attached to herbarium caidsloek,
and then wrapped in herbarium en\elopes.
Ihese mateiials were- then de[)ositi'(l in tlu'
Herbarium ol NouNaseular (Irxptoganis at the
Monte 1 -. Bean Miiseuin. Hrighani Young Ini-
\ersit\, i'rovo, I tali. I nialgal cultures lia\ing
isot\'pe or parat\|)e status weie grown on agar
slants ol' WWW and (Kposited in the I TlvX
(iulture Golleetion at the L'ni\ersity ol lexas,
Austin. Texas.

1998]

Mi( Koiuoric Crusts oi Baja C'ai.ii'okma

299

Tabm-: 2. Suinniar\' of" spocifs abuiuLiiicc- aiul licliiifss data for eacli of the 10 stuck sites in the Catavina region of the
C'eiitral Desert of Baja (^ahfornia, Mexico. Alil)reviations used: CFU/g = eolony-forming units of alj^ae/gram soil,
(:VA\()B = iiuiiilier of exanolxieterial taxa, I'^L'lvVHY = number of non-diatom eiikarvotie taxa, DIATOM = number of
diatom t;L\a, TO'IAL = total mnnlier of alual taxa, VASC^UL = number of perennial \aseular plant taxa, % CRUST =
estimated percent cover ot microbiotie crust.

Site

CFU/«

CYANOH

EUK-VHY

DI.ATO.M

lOTAL

VA.SCUL

7c CRUST

I

2 X l()i

4

6

6

16

2

100

2

6 X 10 i

2

4

6

12

2

90

.■5

2 X 10'

1

8

6

21

2

SO

4

2 X 10'

9

11

6

26

3

\D

■5

8 X m

/

4

8

19

4

r>5

fi

5 X 10'

6

6

6

18

6

100

"■

5 X 10'

6

10

8

24

5

100

8

2 X 10 '

6

8

7

21

5

101)

')

1 X 10'

4

14

6

24

6

100

Id

■2 X 10'

3

4

9

16

1

100

Cluiiattcri/atioii of
tlu' Diatoms

Siibsaniples of each composite sample were
remoNcd, acid cleaned, washed, and mounted
into permanent diatom slides following Johan-
sen et al. (1982). We then examined diatoms
using a Zeiss Axioskop photomicroscope with
high-resolution Nomarski DIG optics. Relative
density' of species was detemiined using counts
of 100 frustulcs/sample.

Soil Chemistn

Soil chemical and physical anaKses were
conducted b\- the Soil Testing Lahorator\- at
Brigham Young Uni\ersity using standard
methods (Soil Sin-\ey Staff 1962, Soil Conser-
\ation Service 1972). Analyses included per-
cent gravel, soil texture (gravimetric method),
pH (saturated paste), electrical conductivity,
and percent organic matter (Walkle\ -Black
method). Nitrate-N, calcium, magnesium, and
sodium levels were determined from soluble
extracts. Phosphorus and potassium were ex-
tracted using sodium carbonate \ia the Olsen
method (standard for alkaline soils). Sodium
absorption ratio (SAR) was calculated using
levels of calcium, luagnesium, and sodium.

Statistical AnaK sis

Several different biometric methods were
used to detect patterns in the data. The 10
sites were clustered based on jaccard's simi-
larit) (Goodall 1978) utilizing the unweighted
group average method of cluster generation
(Pielou 1984). Centered, standardized princi-
pal component anal\ sis (Pielou 1984) was used
to ordinate sites based on soil chemical and

physical parameters. FinalK, canonical corre-
spondence analysis (CCA) was used to simul-
taneousK' ordinate sites, species, and environ-
mental variables (Ter Braak 1986, 1987). Nor-
malK, (juantitative data are used for CCA
analyses. Although we had quantitative data
for diatoms, we had none for all other algae.
To increase resolution of the CCA, we recorded
0 for absence, 1 for a single isolation from a
site, and 2 for 2 or more isolations from a site.
For diatom taxa, we recorded 0 for absence, 1
for relative abundances of 1-15%, and 2 for
relative abundances > 15%. CCA was run with
full species data sets and then subsequently
run with shortened sets. The taxa eliminated
in short sets were those which did not \ar\' in
number in 9 or more sites.

Result.s
Floristics

The total concentration of algae in the 10
locations within the study site ranged from 6 x
K>^ to 5 X 1(H CFU/g soil (Table 2). Microbi-
otie crust c()\er was obvious at all sites, with
the majoritv' of sites showing 80-100% cover.
Perennial \asciilar plant diversity' was low,
with onl\' 1-6 species recorded from each area
(Tlible 2)'.

A total of 66 algal species representing 32
genera were recovered from these sites (Table
3). Some widespread taxa were found in 8 or
more sites. These common ta.\a included the
c\ anophytes Nostoc commune and Schizothrix
calcicola. the chlorophvte Mynnecia asti^mat-
ica. and the diatoms Hantzschia ainphioxijs,
Hantzschia (unphijoxys f capitata, Luticola

300

Giu:at Basix Naturalist

[\olunie 58

Table 3. Algal distribution in 10 sites from the Cataviiia region of the Central Desert of Baja California, Mexico. Cat-
egories: 1 = 1 isolate from the site, 2 = 2 or more isolates from the site. Relative clensit) is given for diatom taxa and
chrAsophyte cysts. Absence is indicated by a blank.

Site

Species

1 2

10

CV.WOB.UTEHI.V
Anabaena sp.
Lyiighya diniieti Ciom.
Lt/ngbya piitealis Mont.
Microcoleiis steeiustrupii Bo\'e-Pet.
Microcoleus vagimitus (Vaucher) Com.
Myxosarcina burmensis Skuja
Myxosarcina spectabilis Geitler
Myxosarcina sp.
Nastoc commune Vaucher
Nostoc muscorttm Ag.
Nostoc pi.scinalc Kiitz.
Nostoc piinctiformc (KCitz.) Hariot
Plectonema tomasiniamim van gracilc llansg.
Picctonema sp.

Scliizotlirix arenaria (Berk.) Com.
Schizotlirix calcicola (Ag.) Com.
Scytimcma ocellatum Lyngb.
Scytcmcma sp.

ClILOHOPiniA

Apatococcus constipatiis (Printz) Printz
Bracfcacocctis aggregatiis Teieg
Bracteacocciis cohaercns BischofI & Bold
Bracteacoccus grand is Bischoff& Bole!
Bracteacocciis minor (Chodat) Petrova
Bracteacoccus minutus Schvvarz
Bracetacoccus pscudominor Biseliofi & Bold
Chlorella eUipsoidea Cerneck
Chlorella vulgaris Beijeririck
Chlorococcum minutum Starr
Chlorosarcinopsis aggregata Arce & Bold
Chlorosarcinopsis arenicola Croover tk Bcjld
Chlorosarcinopsis auxotrophica Groover & Bold
Chlorosarcinopsis baslropiensis Groover & Bold
Chlorosarcinopsis gelatinosa Chant. & Bold
Chlorosarcinopsis semipervirens Groox er & Bold
Cylindrocystis hrehissonii van deserti. s]). nox.

1

1

1 1

1

1

1

1

1

1

1

1

1

2

1

2

2
1

2

2

2

1

1
1

1
1

2

1

1
1

1

1
2

1
2

1

1

1

cohnii, Luticola mutica, and Pinnularia horc-
alis van scalaris. Most taxa were rare, witli 30
of the 66 species identified appearing in a .sin-
gle site. Altliongh rare in onr sites, most ta.xa
isolated are species that connnonly occnr in
desert soils. Notai^le exceptions (i.e., ta.xa not
formerly (onnd in desert soils of North Amer-
ica) inclnde CijlhidrociisHs hrehissonii \ar
(Icscrti, Elakalolhiix ohliisdhi, I'JIiptochlori.s
suhs})h(U'ri((i, Fascicnlochloris iiicxicdiid, Loho-
.sphacrop.sis lohophora, Lohosphdcni lirolciisis,
Luticola rniiticoidcs, and Vischrria hchclicd.
These taxa, nnnsnal in desert soils, aic de-
scribed helovv. Three of them are new to
science.

(-l/liii(h'()cystis hrehissonii
\ar. (Icscrti. \ ar nox.

(I'igs. (-9)

C'oloniae prasini. (.'I'lhilae solitariae, exlin-
dricae extremis rotnndatns, 10-15 |im lalae,
14-56 |am longae. Paries cellnlae tennis, pellii-
cidns. Nnclens centralis. C>hloroplastiis elonga-
tns porcis longilndinalihns lohalis, conslrictns
ad cenlrnm partes dnae lonnanli'S, mia(inae(|ne
pyrenoide; dimidia in cellnlis ali(|na axialilins.
P\renoides pin minns\i> distincta grannlis
am\ lis, raro xagina ani\la c-xidenti. Z>'gospora
non ohseiAata.

Txpns die .\piil h)9.1 a solo deserti. loeus 7,
WIK; #f)57^). iai. i)or 2^ri7'()9.0", long. occ.

1998]

MKIxOBIOTIC CIUSTS of Ha|A (."AIII'OKMA

301

Tabm-: 3. ('onlimu'tl.

Spt'cii's

9 10

Dklijochloropsi.s splciulida (it-itU'r

Dipliispluwra spccifs

Eldkiitollirix ohtiisata. sp. nu\'.

Elliplocliloris siihsphtu'rica (Ht'is.) Ktll 6< (".art.

Etilia hilolxita (N'iiiat/.fr) Komart'k

EttlUi cnluwrciis (Cioomt & Hold) KttI 6c (iarl.

Fasciciilochloris iiwxicaiui, sp. iu)\.

Kichsonnidiiiin disscctmn (Ca\) Ettl 6c Gart.

Klchfioniiuliuin flaccUlum (Kiit/..) Sil., Matt. 6v Bl.

Lohospluicra tirolcii.sis lii'isii;!

Lohosp}\(wr(ipsis lohopluira (.Amir.) Kttl 6< (liiit.

Miiricllii (Icrolor MscIut

Mitru'lla tciTc.stris Box o- Pet.

Mi/nin'cia (i,sti>im(itk(i N'inatzer

Mijnni'cia hkitorcllac ( Tscli. \ Pli'ssl) lioye-Pct.

Mijnni'cia <ilal)os(i Print/.

Mi/rmccia incisa Rei.sigl

Mtiniiccia inacnniucleata (Di'ason) Aiidr.

Spongiocliloris minor C'.hnni. b^ i^old

Sticlioi(HTii,s hiuillaris Nagtli

ErSTICMAIOI'IIVTA

yisclicrui lulrctica (X'isc-lu'r 6c Pasclier) nil)l)crd

1 1

1

1

2

2

1

1

I 1

B\(:ii.i.\Hi()i'iivr\ (Di.vroM.s)

llaiitz.schid aiiii>hi<)xys (I'lhr.) (ininow

Haiitzschia amphhxys f. capitatii O. Miiller

Liiticola colinii (Ililse) Mann

Luticola iniitica (Kiitz.) Mann

Liitkola iiiiitk'oides (Unstcdti Mann

Nitzscliia liantz.-'iclikiiKi Hal)li.

Nitzscliia piinctafa \ar. minor Wwtyi. 6: Perasi.

Pinintlahd borctdis Ehr.

Pinniiliirid borealis \ar. scalari.s {VAiv.} Hal)li.

Staiiro.sira constnwns (Ehr.) W illianis 6c iionnd

34
30

14

24
38

16
10

41
32

33
33

24

38

2

10

1

10
13
13
32

10

33
32

13

19

25

33 35

50

19
20

ClIHYSCJPII'iT.V

Clinsopluto cAsts

20

18

34

15 21

21

28

114°46'27.9", \\v\i,\o Cata\inae, Desertum Cen-
tralis, Caliloniia Infema, Mexicum. Holohpiis:
BRY C 48041, Herbarium Crxptogamoruin
Xonvascularium, Brighani Younu; University,
Pr()\(), Utah. Is()t\pus in statu \i\(): BC 9-8,
UTEX Congeries Culturaruni, Uni\ersit\ of
Texas, Austin, Texas.

Colonies \i\icl grass green. Cells solitary,
c\linclrical with rounded ends, 10-15 |ini
wide, 14-56 ^m long. Cell wall thin, elear.
Xueleus central. Chloroplast elongated with
longitudinal, lobed ridges, constricted in the
center to form 2 haKes, each with a p\'ren()id,
these haKes appearing axial in some cells.
Pyrenoids more or less distinct, with starch
grains, rarely with an e\'ident starch sheath.
Zygospores not observed.

Tvpe collected in April 1995 from desert soil
siu-face. Site 7, VVHC #9579, 29°4r09.0" N
latitude, 1 14°46'27.9" W longitude, Catavina
region. Central Desert, Baja California, Mex-
ico. Holotype: BRY C 4804 1. Herbarium of
Nonxascular Cnptogams, Brigham Young Uni-
versity', Provo, Utah. Living isotype: BC 9-8,
UTEX Culture Collection, Uni\ersit\ of
Texas, Austin, Te.xas.

This taxon is ver\' similar to the nominate
\ariet>' of C. brebissonii Menegh. in terms of
its chloroplast moipholog\' and general shape
(Figs. 5, 7). It differs in its smaller size. It is
most similar to C. brebissonii \ar minor West
et West, which has a size range similar to van
deserti but differs in its slightly different
chloroplast structure. The chloroplast of C.

302

Grkat Basin Naturalist

[N'olume 58

FiKs. 4-11. CiiliudrnnisHs hrchi.ssonii v;ir. dcscrli ;mkI l.luLilolluix ,>l>l,is,it„ (scale = 10 M>>'>- '•'•'i^- '-'■ (' "c '/.ss..-n/
van f/rwr/i; 4, srnc-talivc- cc-11 ilivisioii (note starcl. sl.rall. atoiiml pyrriiouls,; :. aiul 7, cliloroplasl slum in,H lolu'd rulurs
and 1 pviriioid: fi, persistent cell wails inllouiiiii cell division (anowsi and .il.luine eel! division (ri.Jit). Fi.us. <S-11. /..
nbhtsala. S-fJ, sliorl rlian, olM't;,.tali\e cells 10 I I \ etielatiw cell division (note liiani;u!ai sliap.' ol cells).

1998]

MicKoiuoTic Ciu SIS or IUia (^ai.iiokm \

303

hrchis.sonii \.ir. minor is illiistiatcd as hciiiij;
stellate (l)illard 1990, plate 24, liu. (i), wlnle
that ol \ar. dcscrti is clearK' elongated with
loiiUitudiiial, lohed ridges (Fiif. 7). Howcxcr, in
till' smallest ei'Ils. the ehloroplast ol \ar. (Icscrli
can ajiiH^ai" stellate [\'ig. 4). and so the \arieties
eoiild !)(■ coiihised. The most eonipellinij; aryu-
nieiit h)r ri-eounizinu; the new \ai"iet\' is the
\er\ distinet habitat dillerences. Cyliudrocystis
hrchissonii van deserti occurs in neutral to
alkaline desert soils, while other \arieties of
this species are in acidic iujuatic habitats. The
distinet habitat difierences ha\e caused us to
place relati\el\ more importance on the minor
moiphological differences between the \ari-
(.'ties. Sexual stages, which are important in
delineatinu; Cylindrocystis taxa, were not
obser\ed. OiiK a sin<j;Ie isolate- was obtained.

Eldkdiollirix ohliisdla, sp. no\'.
(Figs. 8-11)

Colonia fla\'o\irens. Mucus extracellulosus
mollis diffusus, copiosus in culturis vetustior-
ibus. (>ellulae generaliter decrescentes ad ex-
trenia, o\ ales ad le\iter triangulares, raro piope
sphaerici, natura triangulari maxima evidenti
confestim post divisionem, interdum cui"vatae;
solitariae \c'l binatim, infrequenter in catenis
brexibus; iminucleatae; 5-6.5 \lm latae, 6-14
)im longae. Paries cellulosus tenuis. Chloro-
plastus parietalis elongatus hemicellulam vel
eellulam complens, interdum fractus. Prye-
iioides indistincta. Reproductio non nisi per
labricam autosporarinn.

Typus die April 1995 a solo deserti, locus 4,
WTl'c #9576. lat. bor 29°47'10.5", long. occ.
1 14°46'1().5", Regio C'atavinae, Desertuni Cen-
tralis, California Inferna, Mexicum. Holot\pus:
BRY C 48042, Herbarium Cryptoganiorum
Nonvascularium, Brigham Young University,
Pro\o, Utah. Isot\pus in statu \i\'o: BC 6-4,
UTEX Congeries Culturarum, Universitx' of
Texas, Austin, Texas. Paratypus: BRY C 48043,
1 lerbarium Cnptogamorum Nonvascularium,
Brigham Young Uni\ersit\, Provo, Utah. Para-
t\pus in statu \i\o: BC 7-1, UTEX Congeries
Culturarum, Uni\ersit)- of Texas, Austin, Texas.

Colonv' yellow green. Extracellular mucilage
soft, diffuse; copious in older cultures. Cells
generalK' tapered at ends, o\al to somewhat
triangular, rarely nearK' spherical, with triangu-
lar nature most evident immediately after divi-
sion, occasionally curved; in singles or pairs.

oecasionalK in short chains; uninucleate, 5-6.5
^ni ill diameter, 6-14 |.liii long, (-ell wall thin,
ehloroplast parietal, elongate, filling half to
entire cell; oecasionalK fragmented. Pyrenoid
indistinct, lieproduction onl\ through auto-
spore production.

Tn pe collected April 1995 from desert soil
surface. Site 4, WIIC #9576, 29°47'10.5" N
latitude, 1 14°46'1().5" \V longitude, Catavina
region. Central Desert, Baja (California, Mexico.
Holotxpc: BRY C 48042, Herbarium of Non-
vascular Ciyptoganis, Brigham Young Univer-
sit\, ProNo, Utah. Lixing isot\pe: liC 6-4,
UTE.\ (>iilture (Collection, Uni\ersit\ of Texas,
Austin, Texas. Paratvpe location Site 5,
29°4ri7.7" N latitude! 114°46'16.2" \\ longi-
tude, Catavina region. Central Deseit, liaja
California, Mexico. Paratype: BRY C 48043,
Herbariimi of Nonvascular Cnptogams, Brig-
ham Young University, Provo, Utah. Living
paratype: BC 7-1, UTEX Culture Collection,
University of Texas, Austin, Texas.

Our species differs from other species in
the genus in ha\'ing much shorter cells, which
are not as clearK' tapered as is t\'pical foi- the
genus. E. ohiusata is most similar to E. <i,cl(ifi-
nosa, which also possesses an amorphous
mucilage and has cells somewhat longer and
thinner (13-18 |im long b\ 3-6 [Am wide com-
pared to 6-14 \Xm long b\ 5-6.5 |im wide in E.
ohtusata). Because of its relatively small lengdi-
to-width ratio, E. ohtusata is much stoutei- and
less tapered than all other species in the genus.

Elliptochlori.s suhspluwrica (Rc-isigl)
Ettl & Giiriner 1995
(p. 424, fig. 127:a-c)

Colony spherical, slightly mounded, grass
green, even at 6 nion. (Cells c\ lindrical when
young, occasionally slighd\' bent, up to 1.5 times
as long as wide, 3-8 )Jm wide, 5-10 |ani long;
becoming ellipsoidal to spherical with age,
spherical cells 8-18 Jim in diameter. Chloro-
plasts txpicalK single, parietal, with a central
p\renoid, usualK- touching the edge of the cell
at only a few points, becoming lobed or dis-
sected into several plastids with age, starch
positive when treated with iodine. Reproduc-
tion onK through autospore production.

This chlorophx te is distinctixe because of
its production of small cylindrical cells that
exentually round out to become larger spheri-
cal cells.

304

Great Basin Naturalist

[Volume 58

Fasciculocliloris niexicana, sp. nov.
(Figs. 12-16)

Colonia scabera sicca, substrato adhaerens,
atroviridis. Cellulae dispositae in massis, fasci-
culus cubicis, vel tctratibus isobilateralibus;
parietibus arete adpressis in culturis juven-
tibus; in culturis vetustioribus fere sphaeres-
centes et in niuco inclusae; uninucleatae;
3.5-6.5 jini latae, 6-8.5 )Lim longae. Paries cel-
lulosus tenuis firmus, spissescens ad 4 |lm in
culturis scenescentibus. Cytoplasma granu-
lans, vacuolis contractilibus duabus visibilibus
in cellulis juventibus. Chloroplasus parietalis,
eellulani complens ubi inatiuus. Pyrenoides
excentrica, granulis grandibus amyli consoci-
ata; solitaria in cellulis juventibus, aliquot in
cellulis vetustioribus. Zoosporae 4-16 in quo-
que cellula materno, ellipsoideae parietibus
flagellis binis circa aequalibus, 1-2 vacuolis
contractilibus, (2.4)-3.2-4 |im latae, 5-8 |im
longae. Stigma linearis, media ad anticum.
Chloroplastus parietalis, in medio zoospora.
Nucleus posticus.

Tvpus die April 1995 a solo deserti, locus 5,
WHC #9577, lat. bor 29°47'17.7", long. occ.
114°46'16.2", Regio Catavifiae, Desertiun Cen-
tralis, California Inferna, Mexicum. IIolot)'pus:
BRY C 48044, Herbarium Cryptogamorum
Nonvascularium, Brigham Young University,
Provo, Utah. Isotypus in statu vivo: BC 7-6,
UTEX Congeries CJulturarum, University of
Texas, Austin, Texas.

Colony rough, dry, adherent, dark green.
Cells arranged in masses, cubical packets, or
isobilateral tetrads; with tightly appressed walls
in young cultures, becoming nearly spherical
and encased in extracellular mucilage in older
cultures; uninucleate, 3.5-6.5 |im wide, 6-8.5
|am long. (>ell wall thin, firm, becoming thick-
ened to 4 |lm in senescent cultures. Cytoplasm
granular, with 2 contractile vacuoles visible in
young cells. Chloroplast parietal, filling the cell
when mature. Pyrenoid eccentric, associated
with large starch granules; solitary in young
cells, multiple in older cells. Zoospores 4—16 per
mother cell, binagcllate, walled, ellipsoidal.

with 1-2 contractile vacuoles, (2.4)-3.2-4 jim
in diameter, 5-8 |lm long. Flagella of approxi-
mately equal length. Stigma linear, median
to anterior in position. Chloroplast parietal,
median. Nucleus posterior

Type collected in April 1995 from desert
soil surface. Site 5, WHC #9577, 29°4ri7.7"
N latitude, 114°46'16.2" W longitude, Catavina
region. Central Desert, Baja California, Mexico.
Holotype: BRY C 48044," Herbarium of Non-
vascular Ciyptogams, Brigham Young Univer-
sity, Provo, Utiih. Living isot>pe: BC 7-6, UTEX
Culture Collection, University' of Texas, Austin,
Texas.

The original description of the genus Fasci-
ciilochloris (McLean and Trainor 1965) cites
packet formation by vegetative cell division in
2 or 3 planes, presence of an extracellular
gelatinous matrix surrounding indi\ idual cells
and cell packets, and production of walled
zoospores with the average size of 4 x 7 |lm
and une(iual flagella; 1 species, F. holdii, is
included in the genus. Our isolate displays the
generic characteristics of cell packets formed
by vegetative cell division, mucilage siu-
rounding both individual cells and cell pack-
ets, and production of walled zoospores with
flagella that are longer than the bod\' length
and, at least in some cases, slightly imeven in
length (10% difference). Comparison of agar-
grown cultures of oiu* isolate with F. holdii cul-
ture 1451 obtained from the UTEX culture
collection revealed several differences, the
most notable of which were nuicilage produc-
tion and zoospore morphologx. Mucilage pro-
duction in our isolate was copious and evident
surrounding both individual cells and cell
packets (Figs. 12, 13). Average cell diameter of
\t\getati\'e cells was 6.4 |Jm not including the
nuicilage envelope and 8.9 fJm including the
envelope; the diameter of nonenveloped cells
was slightlv smaller than that reported in the
literature (McLean and Trainor 1964). (^ells
from UTE.X culture 1451 were approxiinatelv
7 jiui in diameter; nuicilage production was
less pioiioiiiKcd than tluit obst'ivcd in our iso-
late or cvidcut in iiliotogriijihs in the oiigiual

Figs. 12-25 (sei- lafing page), hasciciilocliloris incxinind and Viscliirid hcltcticd (scalo = 10 |ain). iMgs. I2-l(i. F. niexi-
cana: 12, pacl<c't roniiatioii in xcgctalivi' cells; 1.3, cc-lls t'mluddi'il in cxtiaciHiiiar matri.x; 14-16. zoospoir formation and
niorpliology. Figs. 17-25. V' Iwlvetica: 17-18, \fgc'lafi\t' cells showing lolicd tliloroplast and prominent p\renoid;
19, antospore formation; 20, mature cells showing carotenoid accnnnilalion; 21. /oospores (note prominent stigma
[arrow]); 22, young vegetati\e cell; 2.3, malnrc cell in carlv stages of orange pigment at c uninlatiou; 21. zoosiiorangiuni;
25, mature cell (note irregular cell sliaj)!!

19981

Mi( lioiuoTic CiusTs OF Baja California

305

W^

W

13

*%

^

%

41

i»

^ ^

^"•""^

15

16 «

^ ^

^ -"^ I 17 /?fia|

^1

^

\18

y

21

^ /

n

22

19
^^23

20

1 :

24

25

306

ChI' A'l" Basin Naturalist

[\bliime 58

piihlicatioii. The niDSt striking; (lillcrcnct' hv-
tAvct'ii our isolate aiul /{ hohlii is in /oospore
morpholog). The original deseription of F.
boldii zoospores includes the presence of 2
contractile vacuoles, a median to posterior
stigma, flagella of unecjual length, and a size of
4x7 flm. Characteristics of the UTEX 1451
culture are generally consistent with the origi-
nal description with the exception of size;
zoospores of our subcultine of the t>'pe mater-
ial a\eraged 3x6 |im. The zoospores of our
isolate had an average size of 3 x 5.3 |lm and a
clearly anterior stigma (Fig. 16). Length of the
2 flagella appeared approximately equal on
some cells, but flagella which differed in
length by approximately 10% (5.5 \Xm vs. 6.0
Jim) were also observed. After extensive exam-
ination of glutaraldehyde-fixed cells, we feel
confident in describing the flagella of our iso-
late as une\'en, but less obviously so than the
flagella of F. hulclii.

Lohospluieropsis lohophora

(Andreeva)

Ettl & Gartner 1995

(p. 418, fig. 123:a)

Cells spherical to subspherical, uninucle-
ate, 4-12 |im in diameter. Cell wall thin in
young cells, thickening to 1 |ini in older cells,
(^hloroplast parietal, becoming lobed, or some-
times filling the entire cell, with a clear pyre-
noid. Oil droplets present, some cells with a
slight orange pigment. Reproduction only
through production of 2-4 autosporcs.

The genus Loho.spliaeropsis was sepaiated
from Chlorella based on its lobed chloroplast
(Reisigl 1969). It is distinc-t from Lohosphacrd
in that it possesses a pxrenoid.

Ij>h<).si)li(icr(i tirolcnsis

lieisigl 1964

(Ettl ik C^iirtner 1995,

p. 415, fig. 122:d)

(>()!()n\ green lo ncIIow gicen. (,'ells splieri-
cai or less ollen ()\al, in small groups, iniinn-
eleate, 6-16 |ani in diameter Cell wall ihin.
Chloroplast parietal, lobed, without a j^xrenoid.
Starch granules xisiMc when slaincd willi
iodine. l{eprodne(ion onK llnongli aiilospoic
production.

Our isolates fit the mor])hol()git al (leseri|)-
tion for this species (|nite well, although the
desert soil ol Haja ( .'alilornia is a \ci\ dillcK iil

habitat from the wet rocks and mosses in the
Austrian Alps from which this species was
described. We are concerned tliat with the
disparity of habitats, our ta.xon may actualK'
have a genetic identitx' (juite different from
the type of the species.

Lnticola fitiiticoUh's (Hustedt)

Mann in Round et al. 1990

(Hustedt 1961-66:598, fig. 1602)

Valves broadly elliptical-lanceolate, with
rounded ends, 10-18 |im long, 6-7 |im wide.
Raphe filiform, proximal ends clearK defli'cted
to one side. Axial area broadened toward the
center Isolated punctum in a marginal or near
marginal position on side opposite the side
toward which raphe ends are deflected. Cen-
tral area transverse, but generalK not reaching
the margins. Striae distinctK pimctate, 22-24
in 10 |im.

The elliptical lanceolate shape, strongly
deflected raphe ends, and marginal punctum
separate this taxon from Luticola miiticd and
its \'arieties. Our specimens were more coarse-
1\' striated than those observed by Hustedt
(1961-66).

Vischeria helvetica

(Vischer & Pascher) Hibberd 1981

(Ettl & Ciirtner 1995:240,

fig. 61:c-e)

(Figs. 17-25)

Colonx spherical, \ellow green to olixe. Cells
spherical to ()\al, iufre(]uentl\ irregular 8-22
)Llm in diameter Cell wall thin. (Chloroplast
parietal, sometimes covering onl\ 1 side ol the
cell, often lobed, with a sciuare-cul jnicnoid,
orange pigment often ol)\ ions, starch not pre-
sent. A large vacuole with browuian mo\ e-
ment of contents ollen present. Oil droplets
evident in sonu' cells. Repioduetion thiough
production ol 2 — f autosporcs or through zoo-
spore production. /oospori'S flask-shaped, ini-
tialK elongated, metabolic, .3.2-8 ).iin wide,
8- l(i ).lni long, rounding up (|uiekly. Chloro-
plast band shaped, eoxcring 1/3 nv less ol flu'
cell. Stigma eustigmalophxt'eat'n; auteiioi',
prominent, outside ol chloroi)last.

( liaiacteristics ol oni' strains are \ei\ similar
lo llic (lescriplion ol i'.tislipiidlos iii(lL!.mi.s ( J.R.
I\'lersen) llibbeicl (19SI). /■.'. m<ii:.iiiis is char-
acterized as lia\ ing spherical cells w ith a flexi-
ble, smoolli cell wall, lobed pariel.il ililoioplasi.

lyy.si

Mkhohioi K (ilU MS Ol B\| \ (;ai.ii()K\ia

307

T.MU.I". 4. Soil tlurnistn analysis ol 10 sitt's in iIr' (.'cntral Divscrt ol Baja (^alilornia, Mexico. ()M = organic mattiT.
I'X" = electrical c()ncliicti\i(\ (|inilios/cni), SAR = sodintTi ahsorjition ratio. Pt'rcent sand, silt, and clay were calcnlated
alter reino\al olgraxcl. Mineral nutrients in ppni.

Site

Parameter

1

2

3

4

5

6

7

8

9

10

Mean

pll

7.1

(i.:5

7.3

7.3

7.5

7.5

7.7

6.5

6.9

6.6

7.1

% gra\el

10.0

Ki.O

22.0

21.0

35.0

11.0

9.0

11.0

15.0

9.0

15.9

% sand

so.s

77.1

()().(i

7.3.3

57.6

78.1

87.9

SO.)

79.1

75.1

75.6

%clav

S.2

11.4

1 1.4

11.7

22.4

8.2

6.4

9.9

8.9

10.2

11.2

% silt

11.0

1 1 ..-,

lU.l

i.-xO

20.1

13.7

.5.7

10.0

12.0

14.7

13.3

% OM

0.5

O.fi

().(i

O.S

0.4

0.6

0.4

0.5

0.7

0.4

0.6

NO,

3.7

3.1

2.0

2.3

3.3

2 7

2.1

2.6

2.8

2.9

2.8

P

lO.S

22.7

9.0

10.7

.31.2

7.4

8.3

17.7

17.9

9.4

14.6

Kxcli. K

(14

"■ ~

10.2

(i.O

5.8

5.8

2.7

5.8

10.2

9.4

7.1

.Sol. Ca

72.4

18.7

78.1

79.2

101.9

48.0

75.4

22.2

52.6

21.6

.57.0

Sol. .Mg

9.9

9.0

14.2

6.2

15.5

7.4

5.4

14.1

12.2

10.1

10.4

Sol. Na

49.6

Hi.O

26.2

5.4

37.4

24.8

1.6

17.8

9.6

12.3

20.1

i:c

0.7

0.3

0.6

0.4

0.8

0.5

0..)

0.4

0.4

0.3

0.5

SAH

1.4

O.S

0.7

0.2

0.9

0.9

0.1

0.7

0.3

0.6

0.7

large vacuole, and angular pyrenoid. Vischeria
helvetica shares the lobed chloroplast, angular
p\ renoid, and in most cells, the thin, smooth
cell wall and s]:)herical shape. However, Hih-
herd (19S1) states that at least some cells in a
cidtnre of sphciieal, smooth-walled cells are
irregular or poKhedral. His illustration of \'
Iwhctica (Hihberd 1981, fig. 10) is identical to
our cells. The sizes of the 2 species are also
similar, with our cells being more similar to
the size range reported for E. magnus. Flagel-
lated cells in ViscJieria are unmentioned by
Hibberd (1981) but illustrated in Ettl and
Gartner (1995). We did not observe the dis-
tinct ridges figiu'ed in the line drawings of V.
helvetica (Etd and Clartner 1995). We decided
to place our strains into V. Jielvetica based on
the consistent presence of 3-cornered, angular
cells and on the similarit\' in appearance to
jihotomicrographs of the type culture (Hib-
l)erd 1981). If we are coirect, our photomicro-
grai)hs of the zoospores are the first to be pub-
lished (Fig. 21). These taxa need further char-
acterization, and we are not certain the distinc-
tion between Eiistigniatos and ViscJieria will
persist when more strains of both are isolated
and cliaiacterized.

Relationships Between Algal
Distribution and Soil Wuiables

Clustering of sites on the basis of algal
species revealed a low level of similarity among
the sites, probably due to the extent of the rare
taxa present. Sites 6 and 7 were most alike,
showing 527c similarit\ ; the remainder of site

pairs had similarity indices of 29-44%. Because
the sites clustered so poorh'. this cluster is not
shown.

Soil chemistn anahses reveal tliat the soils
are sandy, have little organic matter (<{).8%),
and have a pH in the neutral to slightly acidic
lange (Table 4). The greatest difTerence among
soils is seen in the amount of phosphorus,
potassium, calcium, and sodium. Comparison
of the relative similarity of sites using PCA
analysis based on soil chemistry showed little
agreement with the clustering dendrogram
based on floristic analysis. This finding sug-
gests that differences in algal composition
seen among the sites cannot be explained b\
the 14 soil variables examined.

To further e.xplore the relationship between
soil chemical antl physical parameters and algal
species distribution, we performed several
canonical coirespondence analyses (CCA). Most
were uninlorniative. Since we had more envi-
ronmental variables than sites, it was not
appropriate t(,' perform CCA with all environ-
mental variables. Forward selection of envi-
ronmental variables was conducted, and the
following were selected: organic matter, K,
electrical conductivity, percent gravel, Ca,
Mg, antl sodiuiu absorption ratio. The short-
ened species list was used. This CCA did not
agree with either the cluster auaKsis or the
PCA based on soil chemistn'. We inteipret this
to mean that correlations between combined
soil chemistry parameters and algal species
distribution are poor. Subsequent analyses uti-
lized single environmental variables which

308

Great Basin Natufimj.st

fXblume 58

DJsp

vsphel

7§)Cybrd

' Mude

Mute

Scyt

I

Clar^

Myxo m^^° Noco
Nomu

PItog
51

Pibos^

1® L^^

Ccrr
Lypu

NopuB LumuA

Brcl^

Lydi

Loti*

Etbi* _

Scar

MxspB „m

Siba 4
else

Chvu

Clau

Nopi

H),

Elsu

$1

Pibo

CIge ^Stco
Cyst

Haamc

Niha
10

kBrps

08

AHaam
#Vihe •KIdi

^Myas

Brmr •P''9'' #

• Myb. Brmt Spmi

^Nipum

^Myma

^

• Etco

Lblo
Clag
Myin

Fij^. 26. Canonical corrospondence analysis (CX^A) ol tlic 10 Catavina sites wlien tlif axes were constrained In pi I
alone (all species used hut not all shown). A.xis 1 is nei^atively correlated with pll ir = -().9fi2); i.e., more alkaline sam-
ples are to the left, more acidic samjiles to the rit^ht. Ki.uenvalues for 1st and 2nd axes 0.250 and ()..'i.S6, respecti\il\.
Sites = hollow hexagons, cyanoplntes = solid sijuari-s, chloroi)hytes = solid circles, diatoms and chnsoiiln tes = solid
triangles, eustigmatoplntes = solid he.xagon. Species codes consist of the iirst 2 letters of the genus, first 2 letters of llu
species, and Iirst letter of the snhspecific taxon, if given. With unknown species, the first 4 letters of the genus are gixen.
Potentially confusing codes follow: iJrnir = BractcaciHCtis minor, Brmt = Bniclcacocrii.s niiniitus. C.\\ = Cidonlla. Ce =
Chlorococrum, (..] — C'lilonisarcinopsis, CJyst = chnsoi^ln te c\sts, Lo = lAiliosph(wm. \h = I.Dhosplwcropsis. l,umu =
Lulifold inttlicd. My = Mijniircia. \\\ — Mijxosdiciitii. Se = Scliizollirix. Si = Sliclunocciis. SI = Sidiirosira.

.showed .substantial variahilitx' ainoiii:; sites; note thai iho Mynnccia species were- lonnd

these have been piesiniied to be inipoilant in clustered together, suntiestinu the\ \\A\r sinii-

the hteratiire (pi 1, percent silt, sodiinn absoip- lar |d i r((|nirenients. (lanonieal eoncspon-

lion ratio). Ol these, only the CCA constrained denee anaKsis is less ellectixt' with the lew

to pll was inlorniative (Fij^. 26). Cyunobacter- sites used in this study, so these icsiihs should

ial faxa occurred in soils of higher pll, while be interpreted with caution. Ilowt'xt'i-, C(;.\

chlorophyte and diatom ta.xa were distributed does ap|)eai- to be a iironiisiu"; ordination

across the entire |)ll rauo;e. It is inteicsliui;; to method joi- soil aluae. Apart Irom pll, wc can

1998]

MicKoiuoTic CiusTS OF Baja C^aufohxia

309

see no trends that eleaiK eonneet alual speeies
distribution in the Cataviiia siti's to soil elienii-
cal and'or phxsieal paranu>ters.

Discussion

This stud) demonstrates that when a \ari-
ct>' of methods are used to eharacterize the
eonmumit}', a hiiih le\c'l ol al,u;al ch\ersity ean
he deteeted in desert soils. \Ve identified a
total of 66 speeies. In past studies of desert
soil algae, many investigators have eoneen-
trated their efforts on identif\ing e\anol)aete-
ria and diatoms (Cameron 1960, 1964, Durrell
1962, Shields and Drouet 1962, Hunt and
Durrell 1966, Anderson and Rushforth 1976,
johansen et al. 1981, 1984, Ashley et al. 1985,
lohansen and Hushforth 1985, johansen and
St. Clair 1986j. The absenee of eareful ehloro-
ph\ te and xanthophyte characterization is likely
due to both the diffieult\ of their identification
(which recjuires unialgal culture) and the lack
of comprehensi\'e taKonomic treatments prior
to 1980. In general, when non-diatom eukarv'-
otic algae were identified, it was only to the
genus knel (Martin 1939, Cameron 1960, Cain
1964, Friedmann et al. 1967, Archibald and
Bold 1975, Matting and Rayburn 1979). Cam-
eron (1964) attempted to identifv' non-diatom
eukar\otic algae from the Sonoran Desert in
southem Arizona, but identified onK' 9 species,
lohansen et al. (1993) observed a total of 72
algal taxa from a single site in the Lower
(Columbia Basin, Washington, which was sam-
pled seasonalK for 12 mon. The\' obser\'ed 47
chloroph\tes and 9 xanthophytes, many of
which were identified to species. It is interest-
ing to note that the latter stud\', employing
methods identical to those used in this study,
had nearK' identical numbers of taxa, even
though the floras demonstrated striking differ-
ences in composition.

This stud\ is the most comprehensixe floris-
tic examination of soil algae from a geographi-
calK restricted hot desert community. The
large number of species obser\ed is due both
to the \ariet\ of assa>' techniques used and the
fact that 10 subsites within the area were stud-
ied. The observation that over 50% of the taxa
were identified from a single site demonstrates
compositional heterogeneit\ within desert
soils. This finding also causes us to speculate
that more extensixe sampling in an\ one of our
subsites would \ield more taxa, and reinforces

our contention that composite samples are a
necessity' gi\'en spatial heterogeneit>' in ciypto-
gamic crust connnunities (Crondin and Johan-
sen 1993).

Ackno\vled(;mf.\ts

Our thanks to Da\ id M. Ward, Jr., who
assisted with fieldwork, and Susan Okuley,
who assisted with algal plate counts. Klaus
fVitsch graciously helped with difficult Cer-
man words/passages. The Zeiss Axioskop micro-
scope was purchased in part with funds from
NSF BIR-93 19239. Continuing support for
supplies and publication costs was provided
1)\ John Carroll University. John Carroll Uni-
versity also provided release time for research
to both Flechtner and Johansen.

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JoHANSEN, J.R., AND S.R. RisiiEORTil. 1985. Cnptogamic
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JoHANSEN, J.R., AND L.L. St. Clair. 1986. C;r\ptogainic
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632-640.

JOHANSEN, J.R., J. Ashley, and W.R. Rwblrn. 1993. F.ifects
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JoHANSEN, J.R., A. J.WAKUL, AND S.R. RtSHI'ORTH. 1982.

Effects of burning on die algal communities of a high
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loHANSEN, J.R., S.R. RUSHFORTH, AND J.D. BUOTHERSON.

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1998]

MicHOBioTic Crusts of Baja Cai.i!()1{\i a

311

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Received 2 September 1997
Accepted 25 March 1998

Great Basin Naturalist 58(4), © 199S, pp. 312-327

RESPONSE OF UNDERSTORY SPECIES TO CHANGES IN
PONDEROSA PINE STOCKING LEVELS IN THE BLACK HILLS

Daniel W. Uresk' and Kifth E. Severson^

Abstract. — The ol)jeeti\e of this stucK' was to test the hypothesis that there are no cliBerences in underston prodne-
tion, by species, due to stocking levels of Pimis pondcrosa (ponderosa pine). Underston production was estimated, by
species, on 3 replicates each of 8 growing stock levels, ranging from clearcuts to unthinned stands, in both sapling- and
pole-sized pine stands (48 plots) over 3 nonconsecutive years. All stands were appro.ximateh 70 \r old when thinning
treatments were applied. Production of many herbaceous species, especially Agropyron spp. (wheatgrasses) and Carex
spp. (sedges), declined as growing stock levels (measured in terms of basal area) of ponderosa pine increased. While
trends in total production were similar, there were specific diflerences between sapling and pole stands. Sedges and
Oryzopsis asperjolia (roughleaf ricegrass) produced more in sapling stands, whereas Danthonia intermedia (timber oat-
grass) was more abundant in pole stands. Shrub protluction, dominated b\' Arctostaphylos uva-ursi (bearbern), was rela-
tively consistent across all stocking levels except unthinned. Although the total number of species declined as pine basal
area increased, a few species, such as Linnaea horealis (twinflower) and Sheplierdia canadensis (buflalolierrx), were
found only under relatively dense pine canopies. While floristic species richness was greater at lower stocking le\els of
ponderosa pine, the total number of species would be greater if all stocking levels were present.

Key words: understonj, ponderosa pine. Black Hills, iilant species, hiomass. production, stocking levels, floristic diversity.

Understory-overstory relationships have
been studied extensively in Pinus ponderosa
(ponderosa pine) stands in western North
America (Ffolliott and Clary 1982). These
studies have reported the response of forage
classes, grasses and forbs, to overstory para-
meters such as canopy cover and basal area.
Most have concluded that herbaceous under-
ston,' vegetation exhibits greater growth when
the competing overstory is reduced. Recent
work on understory-overstoiy relationships in
the Black Hills has related production of
graminoids, forbs, and shrubs to xarious grow-
ing stock levels of Phnis ponderosa in both
sapling and pole stands (Uresk and Severson
1989).

However, conventions governing inanagc-
niciit of public lands are changing. Emphasis
is being placed on ecosystem management.
This ap|:)roach blends social, ph\sical, eco-
nomic, and biological needs and \alnes to
assmc i)n)diictive, healthy ecosystems (Kanl-
mann et al. 1994). Ke\' features of ecosystem
management are the protection and restora-
tion ol biodi\ crsit)', which Kaufmann et al.
(1994) (Iciine as the \arief\ ol hie and its
processes, including \ari(t\ in genes, species.

and ecosystems, and the ecological processes
that connect everything in ecosystems. Practi-
cal application of principles of ecos\stem man-
agement will re(|uire more specific data. In
the case of understory-overston^ relationships,
this means a better imderstanding of responses
by plant species, rather than groups of species
such as grasses, forbs, and shrubs.

The piupose of this paper is to describe
how individual plant species responded to
changes in basal area of Finns ponderosa and
to discuss how these responses could affect
plant species richness in the uuderstorv of
Finns ponderosa forest in the Black Hills. This
study was designed to test the null lupothesis
that understory production docs not differ bx
species due to changes in Finns poftderosa
growing stock levels.

Sii i)V .\Ki:.\

The studv was conducted on the lilack Hills
Ivxperinicntal I'brest, about 30 km west of
Rapid (>itv, .Sontli Dakota. Tlie ovcrstoiv
within the experimental fon-st is dominated l)y
Finns pondcrosa. I nderstory shinbs- inclnde
.\r<i<>st(iplii/los itra-nrsi (beailx-iiv ). Fniinis

'Centor l(ir (irral Plains Ecosysti-m Rf.sfurcli. Hniks Mi
^SeedliiiK trees wen- classified as slinilis for lliis sliidy.

iliSlaliuM. S.lincliil Ml

li.ipid ( ii\, sn:

312

1998]

P()m:)i:iu)s\ Pim: r\ni:i{sr()i{v

313

I ir^inidiKi (coiiiiiioii tlioki'tlu'iix ), Bcrhcris
rcpens (Oregon grape), Aiiwlaiicliicr dhiifolid
(Saskatoon sen'icebeny), and Si/mplioricdrpo.s
spp. (snowberiy). Conniiou licrbs iucludt'
Onjzopsis dspcrfolid (roughlcal ricegrass),
Danthonid iiitcrmcdid (tinil)er oatgrass), Cdrex
spp. (sedges). Pod prdtciisis (Kentucky blue-
grass), Ldflu/ni.s ocJiroh'itcns (cream peavine),
and Cinnpd)udd rotundijolid (bluebell). Most
of the experimental forest is dominated b\' the
Finns pondcrosd/Arctostdphylos nvd-nrsi habi-
tat t>'pe (Hoffman and Alexander 1987) or HU-
5, Finns ponderosdlSyniphoricdrpos dlhd/Arc-
tostdplujlos nvd-nrsi, as described b\ Thilenius
(1972).

The experimental forest encompasses about
1375 ha and elexations range from 1620 m to
1800 m. A\"erage annual precipitation is 600
nnn, 70% of which tails from April through
September. Soils are primarily gray wooded,
shallow to moderatcK' deep, and derived from
metamorphic rock (Boldt et al. 1983).

Methods

Eight growing stock le\els (GSL) oi Finns
pondcrosd including cleareuts and unthinned
controls were sampled in both sapling- and
pole-sized stands. These GSLs were numeri-
calK designated as 0, 5, 9, 14, 18, 23, 28 m2
lur^ and unthinned. Growing stock indicates
all living trees in a stand. Growing stock lexel
is the basal area (m^ ha~^) of a stand adjusted
to accoimt for differences in the a\'erage size
of trees left in the stand after thinning. There-
fore, the numerical designation of GSL
approximates, but does not necessarily equal,
the actual basal area of the stand. Basal area of
0 m- ha~^ indicated clearcut plots. Average
basal areas of imthinned pole stands ranged
from 37 to 40 m- ha"' in 1981, while unthinned
sapling stands \aried from 27 to 33 m- ha~^.
Three replicated plots were randomK* assigned
from a total of 48 plots and installed for each
GSL fi-om 5 to unthinned in sapling- and pole-
sized stands in 1963. Stem diameters were
8-10 cm in sapling-sized stands, and 15-18
cm in pole-sized stands when treatments were
installed. Three replicated clearcut plots in
each of the sapling- and pole-sized stands were
selected and treated in 1966. Cut material was
remoxed from all plots. Each of the 24 plots in
sapHng stands was 0.1 ha and tlie 24 pole stands
were each 0.2 ha. All GSLs were sampled in

1976; but budget restrictions resulted in sam-
pling only 5 levels (0, 5, 14, 23 m- lur', and
unthinned) in 1974 and 1981.

Production of understory vegetation was
measured during August 1974, 1976, and 1981
on six 15-m randomly placed transects per
plot. Twelve 30 x 61 -cm quadrats were ran-
doniK' located along each transect in 1974 and
1976. These data indicated that an increase in
number of (juadrats would provide a better
estimate of minor plant species. Therefore, in
1981, 25 circular plots measuring 0.125 m-
each were SNstematicalK located along 5 of the
transects. Current annual grow th of all herbage
was liai-vested at ground level for each species.
All leaves and terminal portions of twigs to the
first node were clipped on shrubs, also by
species. Material was oxen-dried at 60 °C for
48 h and xveighed. Weights xvere axeraged and
expressed as mean per plot for data analysis.

Heterogeneous variances xvere present, so
data xxere transformed using a log(,^> + l trans-
formation, analyzed xvith a one-way analysis of
variance (years and stands analyzed separately)
and means separated by Tukey's-HSD proce-
dure. In those cases xvhere heterogeneous xari-
ances persisted, means xvere separated using
Dunnett's T3 (Dunnett 1980). Statistical infer-
ences xvere made at a probabilitx lexel of 0.1
foi- type I error to decrease type H error.

Plant nomenclature folloxvs Great Plains
Flora Association (1986) and Wm Bruggen
(1985).

Results and Discussion

Several variables for this study were con-
trolled to reduce xariabilitx. Effects of tree size
class were separated, all plots xx'ere replicated 3
times on the same soil txpe and had similar site
indices, all stands xvere approximately 70 xr old
when treatments xvere applied, and data were
collected oxer 3 separate xears. High natural
xariabilitx' in the understorx' among replications
xvas common despite this control. As a result,
statistical tests often revealed nonsignificant
differences despite xvidelx- separated means.
The common occurrence of heterogeneous
xariances resulted in analysis via Dunnett's T3,
a conserxative test. Therefore, the standard
enor is as important as the mean values in the
tables, especiallx' xalues for indixidual species.

Relationships betxveen overstorx' and general
categories of understory (graminoids, forbs,

314

Great Basin Naturalist

[Volume 58

Table 1. Underston- production (kg lui"', oxcii-dried basis) for 1974 in sapling-sized pondcrosa pine stands growing
at ditterent tree stocking levels. Black Hills, South Dakota. Numbers are means ± standard errors. Wiliies within a row
follow-ed by different letters are significantK' different at the 0.10 probability le\ tl.

Clearcnts

Crowing

stock lc\cls (m-

ha-l)

5

14

23

L nthinncd

Gr.\min(jids

A<ir()i)yroii canintiin

204 ± 100

73 ± 43

7±4

<1

Bromtis inar<!,iiwtus

1 + 1

Brunuis porteri
Carcx spp.

239 ± 123^'

2 + 2
335 + 232'*

25 ± 5I'

5 ±4''

4 ±2''

Danthonia intcniicdia

19 ±7

47 ±20

47 ±2

11 ±5

2±1

Ehjiiim spp.
Festuca octoflom

<1

2±2

Koclcria pijrmnidata
Onjzop.'iis aspi'hj()li(t

8±4

144 + 41ab

304 ± 44''

124 ± SS^'b

62 ± 4,S'>

30 ±5"'

Oryzop.s is piin^en .s
Poa pratcusis

60 ± 42

42 ± 23

3±3

Poa interior

3 ± 3

5 ±5

<1

Schizachne purpurasccns

1±1

Total

FORBS

Acliilica inillcfoliimi
Agoscris 'glauca
AniipJialis mdrgaritacea
Antcnnaria neglccta
A))()ctjnitin (tmlrosacinijoliitin
Arteini.sia spp.
Aster spp.
Aster laevis
As t r a gal us ads 1 1 rge ns
As t r a gal Its alpini is
Astragalus tenellus
Campanula rotundifolia

676 ± 1 10^'

57 ±21
1±1

<1

<1
<1

5±5

5±3

806 ± 231^'

30 ± 14

3±2
<1

8±4
11±4

212 ±91-'

2±1

1±1

<1

12 ±6
1±1
<1

81 ±41''

1± 1

2±2
1± 1
<1

1 ± 1
1± 1
<1

:36±4i'

<1

<1
<1

.shrubs, and total) aboveground biomass pro-
duction were previoiisK' reported (Uresk and
Severson 1989).

Graniinoid H('S|)()nse

Carex spj)., On/zopsis (i.spcrjolia, and A'^ro-
pijron caiiinmn were the most productive
species under sapling stands (Tables 1-3).
Only Carex spp. and Oryzop.sis aspeifolia pro-
duced signilicantK more herbage at GSl, 11
m- ha~' and below. Pod pralcnsis and Dtnillio-
iiid iiilcnncdia were also eonnnon under
saplings but biomass o( both was lower. OiiK
Onjzopsis (ispcijolid and Daitlhonid iittcnnc-
dia were eonnnon in (iSLs above IS 111- ha '.
Trends noted in pole-sized stands were some-
what similar (Tables 4-6). One of the most
important dillerences between sapling and
pole stands, howcxcr, was that (Uircx spp. and
Onjzopsis dspcrjolid piodnccd iclati\ cK less
in pole stands than in sapling stands, wIk rcas

Ddnthonia intennecUd produced more, paitic-
ularl)' in clearcnts. As in sapling stands, signif-
icant differences by species among (iSLs were
rare. Only Carex spp. were found to produce
more at lower GSLs in 1981 (Table (i).

The general responses of graminoids in both
sapling and jiole stands wtM(.> similar to otlii-r
Black Hills studies that included data on species
(Pa.se 1958, WVage 1994). Tase (1958) linuted
descriptions to the most intpoitant species
(the r(>st were combined into an "other cate-
g{)r\ ): but \\'rage s desciiptions (1994) wcri'
complete. I^ase s stnd\ included a \ariet\ of
sites throughout the Black Hills; and W'rage s
slud\ aica, on soils similar to t)m-s but a dilfti-
I'ul habitat t\pe, was about 10.5 km SI'" and
.')5() m lowci' in ele\ation lli.iii (he experimen-
tal forest where this stndx was condncti'd.

Both studies reported responses sinn'Iar to
those herein, but some important dillerences
were e\ ident. I'ase (195S) found lliat significant

1998]

PoM-Ji'Hosx Pink r\i)i;i{s'i()HV

315

TaHI.K 1. (.'oiitiiuicd

(Mi'aifiits

(Irowi

in^ stock IcM'ls (m- lur')

5

14

23

L iitiiinncd

Cirsiiiin spp.

3fi ± 36

Dclphiiiiwn hicalor

<1

Erificroii spp.

3±3

<1

<1

Frafiaria vcsca

9±5

9±7

4 ±3

2±<1

<1

Galium horealc

3±3

<1

Lactuca spp.

<1

1±1

Latlujnifi ochrolcuciis

5±<P'

27 ± .51-

12 ± ?'!'

7 ± 4"!'

1 ±<1''

Linnaca horcalis

17±17

<1

0.x{itr<)})i.s scriccd

<1

Solida^o spp.

<1

Taraxactim officinale

<1

<1

<1

Vicia amcricana

<1

<1

<1

<1

Viola spp.

S±<1

12± 10

1±<1

1±<1

1 ±<1

Zizia aptera

<1

Total

134 ± 39"

102 ± Kt'I'

37 ± 14"!'

34 ± 22"!'

8 ± 4l'

.Siiiu lis

Aiiwhiiuhicr aliiifolia

3 ±2

1±<1

Arcfosta))hijlos tiva-itr.si

244 ± 74

205 ± 56

293 ± 78

255 ± 48

50 ±7

Bcrherifi repcius

8±8

Populus trcmuloides

1±1

<1

<1

<1

<1

Rosa ivoodsii

7±3

7 ±5

4 ±3

4±<1

1±<1

Rtihii.'i idacu.s

28 ±23

23 ±7

5±4

Shcpherdia canadntsis

9±9

S))iraca hctulifolia

2±2

1±<1

1±<1

4±2

I± <1

Sijinphorirarpos spp.

18±8

7±2

4±3

3±1

1 ±<1

Vaccinitiiit .scoi)ariian

21±21

Total

303 ± 108-'

244 ± 5?'

308 ± 76"

305 ± 20''

54 ± 6''

CiKWn'l'oTAI.

1113± 11.5'

11.52 ±196"

.557 ± 138"1>

420 ± 57' >

98±1T

aiiiount.s ol Oryzopsi.s (i,sj)eifoIia persisted under
inoderateK' dense canopy cover (40-59%, 19-27
ni- ha~^ basal area) and dense canopy cover
(60-71%, 28-33 m2 ha-1 basal area), which
compared with our findings. Pase (195(S) and
Wrage (1994) used canopy cover in their
papers; we converted these to basal area esti-
mates using Bennett's (1984) model: % canop)'
cover = 0.51BA(ft2 ac"') - 1.94. R^ = 0.83.
Wrage (1994; did not liiid On/zopsis aspcijoUa
in his plots. Both Pase and WVagc noted that
Diinllumki (oatgrass) was most abundant under
intermediate pine canopies. We found the
same relationship under sapling stands, but in
pole stands Dantlionia was more abundant in
clearcuts than in other GSLs. Poa, the most
abundant grass component in open stands
studied by both Pase and Wrage, was common
but subdominant in this stud>\ Pase (1958)
Hsted Poa pratcnsis, Sporobohis heterolepis
'prairie dropseed), and Carex spp. as the most

common graminoids in pine co\ er class 0-19%
(0-9 m2 ha-1 basal area). Wrage (1994) listed
Poa, Carex spp., and the exotic Bromus inennis
(smooth brome) as being most common in open
stands (<30% pine cover, 14 m^ ha"l basal
area). We found Agropyron canimntu Carex
spp., and Oryzopsis aspetfolia most abiuidaut
in 0 and 5 GSL sapling stands and Danthonia,
Carex spp., and Agropyron ca)iinum most
abundant in pole stands.

We considered 11 species as unconnnon in
sapling stands, defining uncommon as produc-
ing <5 kg lur' in <3 stands over all years
(Tables 1-3). Included among these were Bro-
inii.s marginata (mountain brome), Schizachne
purpurascens (false melic), Oryzopsis pungens
(mountain ricegrass), and the exotic Agropyron
cristatum (crested wheatgrass). There were 10
uncommon graminoid species in the under-
ston of pole-sized stands (Tables 4-6). Two of
these, Bromus tnarginatiis and Oryzopsis

316

Gkeat Basin Naturalist

[N'olume 58

t- V

V V ^ "

— ' 0/
I 5
•2 "^3

-S %

-r — '
+1 +1

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+1 +1 +1 +1

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+1 +1

+1 +1

r—l IC

+1 +1 +1 +1

2

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1998]

PoxnKKosA Pink Undkhstohy

317

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318

Great Basin Natlr/VLIst

[Volume 58

Table 3. Underston' production fkg ha"', o\en-dried basis) for 1981 in sapling-sized ponderosa pine stands growinji
at different tree stocking levels. Black Hills. South Dakota. Numbers are means ± standard errors. \'alucs within a row
followed by different letters are significantly different at the 0.10 probabilitx' le\el.

Clearcuts

Grow

ng stock levels

(m^ha-i)

5

14

23

L ntiiiiuK'd

Gra.viinoids

Agropyron chstatuin

1±1

Agwpijwn spkatuDi

9 ±9

A^ropijron caninwn

282 ± 48

74 ± 19

24 ±24

6 ±4

Bromus mar^inatus

<1

Caicx spp.

508 ± 232''

429 ± 160^

105±5fr'''

26 ±13''

15 ± 13b

Dantiionia intcniicdia

48 ±8

141 ±27

49 ± 16

15 ±11

4±3

Fesfuca ocina

<1

I±>1

Koeleria pijramidatd

1±>1

3 ± 3

Oryzopsls asperifolia

176 ± 8''l>

393 ± 49"

237 ± 12r'

70 ±17''

59 ± 24''

Onjzopsis pungenn

2±2

1±1

Poa pmtensis

252 ± 67

1 ±1

Poa interior

27 ±18

16 ±7

<1

Unknown grass

1±1

23 ± 0

2±2

<1

Total

1297 ± 263^'

1089 ±142-'

424±177'''

118 ±15''

79 ± 35''

FORBS

Achillea iiiillefoliitin

88 ± 42

52 ± 17

9±4

3±3

2±1

A^oseri.s '^laiica

14 ±6

Antennaria neglecta

2±2

5 ± 3

1±1

2±1

1±<1

Apocijnwn aiulrasaeinifoliiin}

<1

3±2

2±1

5±4

1± 1

Astraf^alus canadensis

3±2

Astra<i,alus adsur<i,ens

20 ±4

17 ±6

4 ±3

3 ±3

2 ±2

Aslra<j.aliis spp.

1±1

<1

Astra<ialus teneUus

12 ±6

6 ± 3

5 ±5

5±5

5±5

Campanula rolundijolia

25 ±5

8 ±2

1±1

<1

Cirsiiiin vul<iare

17 ±13

1±1

<1

Delphiniwn bicolor

<1

Erificron spp.

5±5

1±<1

<1

<I

Fra^aria lesca

33 ±2"

24 ± L>'l'

7 ± 5l>

3±<1'>

2±1''

pungens, also occurred in sapling stands. Oth-
ers included Koelaria cristata (prairie june-
grass), which was common in sapling stands,
Poa iirkla (plains bluegrass), Bromus portcri
(nodding brome), and the exotic Plilcuiii
pratense (timothy). All unconiinon specii's
occurred in pine stands stocked at <14 m-
ha-1 hasal area. Wrage (1994: Appendix D)
had 8 grass species that contributed <\%
foliar cover in <3 stands over all years and all
Pinus ponderosa coxcr classes: Agropi/ron
repens (quackgrass), A. inlcniicdiinn (inteniiech-
ate wheatgrass), Bonlcloiid citrlipcndiild (side-
oats grama), Cala macros lis ruhcsccns (pine
reedgrass), Muhlenbergia torreiji (ring muhly),
Schizacliiw purpurasccHH, Sporoholus aspcr
(rough dropseed), and Stipa spartca (porcupine
grass).

Three exotic grasses were loiind inidei the
pine overstory; one, Agrostis stolonifcni (red-
top), was common bnt scattered. 'Hie others.

Agropijron cristaUiin and Phlcum pratense,
occurred only in a single stand each. Poa
pratensis was not considered exotic because it
occurs in l)()th naturali/i'd and natiNc forms in
this area (Cireat Plains Mora Association 19S(-)).
WVage (1994) reported 3 e.xotic grasses: Agro-
pyron rejX'ns. Ap-o))yron i)itcniicdiiiit}. and
Bromus iiwrmis.

Altogether, we found and identilied 22 dil-
ferent graminoids in the jiine undeistorx in
this stndy. 'i'hiileen wt-re conunon to sapling-
aiid pole-sized stands while 3 and 2 species
were unicpie to each respectix'c si/.e class, l-'asi'
(1958) reported 38 graininoid species and
Wrage (1994) listed 23.

An average of 9 graminoid species oeimred
in (JSIjS 0, 5, and 14 m- lur' o\er all xcars.
This was higher {P < 0.05) than tlu- (i and 5
sjiecies Ibund in (iSL 23 and nnthinned stands.
i-es|)ecti\('l\ (I'resk and Se\'erson 1989). The
mean number ol species presi-nt in pole
clearcuts (II) and CSL 5 m- ha ' (10) was

1998]

PoNDKHosA Pine Understory

319

Tahi.k 3. Coiitimifil.

(.Icaixiits

(Jrow

inn stock k'Xfls (tii-

ha-'i

5

14

23

Uiitliiimc-d

C.alium horcale

18 ±13

1±1

2±2

<1

Hirraciuin canadense

<1

1 ± 1

Iris ini.ssotirit'iisi.s

<1

Latlnjni.s ochrolcucus

40 ± 20

117 ±28

68 ± 33

39 ± 13

10 ±6

IJiniiu'ii horcali.s

<1

2±2

<1

Ijipiniis spj).

3 + 3

7±4

MoiKirdd fhliilosa

1±1

1±1

1'oly'j.onum pcrsicariu

1±1

Smilacina stclhitu

2±2

Solida^o sjxirsijlord

7±4

6±5

<1

11±11

<1

Turuxucwn ojficinale

1±1

<1

rritoliuin repens

1±1

4±4

11±1]

<1

Vicid ainericdua

57 ± 35^

12 ± 2t'

9±9''

2 ±21'

1±1''

Viola aditncd

25 ±1

18 ±3

2±2

1±1

1±1

Total

369 ± 99-'

276 ± 6-'

117±52''l'^

92 ± U)!'^

26 ±16^

SllRLBS

Aiiu'ldiuhicr dliiijolia

2±1

1±1

1±1

<1

Arctostdplujlos iiia-iirsi

604 ± 179

820 ± 95

872 ± 427

821 ±333

205 ±111

Bcrhcris repens

8±8

4±4

Populus tremuloides

1±1

3±3

liosd woodsii

25 ±2

21 ±12

13 ±8

11±6

3±3

Riihiis idciciis

130 ±117

61 ± 24

22 ± 13

1±1

3±3

Shepherd ia ednd(h'ii-sis

9±9

7±7

Spiraea hetidifolia

1±1

1±<1

7±2

8±4

4±2

Symphoriearpos spp.

3S ± 10

12 ±4

20 ± 13

5±3

3±2

\ accinium scopariuiii

1±1

Total

S02 ± 307

915 ± 126

938 ± 428

866 ± 326

230 ± 107

C;iv\Nn TOTAI.

2450 ± KiS'

2280 ± 102"

1478±59fr'''

1076±330"''

334 ±146'^

meater {P < 0.05) than the 5, 5, and 3 species
found in GSLs 14, 23, and nnthinned stands,
respccti\ el\' (Uresk and Severson 1989). Wrage
(1994) counted 20, 19, and 16 grass species in
his open (tree cover <30%, 14 m- ha~^ basal
area), intermediate (30-60%, 14-27 m^ ha-l),
and dense (>60%, 27 m- ha~^) Pimi.s ponderosa
stands, respectively.

Forb Response

Forb response, relati\e to GSLs, was simi-
lar to that of graminoids except that forbs pro-
duced about 30% less forage (Tables 1-6). Xo
single forb species dominated any GSL of
either size class; however, AchiUca tnillifoliian
(common \arrow). Campanula rotundijulia, and
Lathynis ochroleucus were the most common
forbs found in pole stands (Tallies 4-6). Achil-
lea ))iiUifoUiiin and Lathyriis ochroleucus were
the most abundant forbs in sapling stands

(Tables 1-3), but few significant differences
by species among GSLs were noted. Lathijrus
ochroleucus produced more herbage in mid-
level GSL sapling stands (5-23) in 1974 (Table
1), and Fragaha vesca (woodland strawbern')
and Vicia americana (American \etch) produced
more in clearcuts in 1981 (Table 3), but no dif-
ferences were noted in pole stands. Pase (1958)
reported Trifoliwn repens (white clo\ er), Fra-
garia vesca, and Achillea niillifoliuin to be
abundant in open stands, but only Lathijrus
ochroleucus and Solidago spp. (goldenrod) per-
sisted under moderatcK dense pine canopies.
Artemisia ludoviciana (white sagewort), Gly-
cyrrhiza lepidota (wild licorice), Psoralea argo-
phylla (siKerleaf scurlpea), and Moimrda Jistu-
losa (wild bergamot) were the most common
forbs in Wrage's (^1994) open stands, but only
Glycyrrhiza lej)idota persisted into intermedi-
ate stands. Forbs were scarce in his dense

320

Great Basin Natltulist

[\()lunie 58

Table 4. Underston' production (ku; ha"', oven-dried basis) for 1974 in pole-sized pondcrosa pine stands growing at
different tree stocking levels, Black Hills, South Dakota. Xmnbers are means ± standard errors, \alues within a row fol-
lowed by different letters are significantly different at the 0.10 probabilit\ le\el.

Clearcuts

(Irow

ng stock le\(.'ls (ni

^ha-'l

5

14

23

I'lithinned

Gramincjios

A<in).sti.s stolon ifcra

<1

A^ropijron spicatwn

3±2

<1

Afiropijron ccininiin

155 ± 89

3 ±2

<1

Broinus inarfiiiuitiis

<1

Brotiius porteri

2±2

<1

Car ex spp.

7±4

15 ±9

2±<1

10 ±5

<1

Danthonki intvnnedia

322 ±21

135 ±31

4(i± 17

5±2

Festtica ocloflora

20 ± 10

<1

Fesiiica oviita

<1

2±1

Kocleria pijrainidald

3 ± 3

Oryzopsis aspcrijolia

9±8

29 ±24

17 ± 15

4 ±3

Poa spp.

10 ±4

Poa pratensis

7±4

4±4

Total

538 ± 7(t'

193 ± 45^'''

48 ± 151'

32 ± 17'»-

5 ± 4^-

FORBS

Achillea iiiilhjoliiiiii

39 ±11

6±3

1±1

1±1

<1

Aiitennaria nc^lecta

7±4

9 ±9

9±6

3±2

Apoeymnn androsaeinijoliiiin

<1

1±<1

<1

<1

<1

Astra'^ulus alpiniis

13 ±3

17±11

<1

1±1

Astra<ialiis teiiellus

4±3

3 ± 3

3±3

Astra^altis spp.

3±3

<1

1 ± 1

<1

Campanula rotumlijolia

35 ±22

6±2

<1

Cirsiwn arvense

14 ±14

Cirsium vulgare

15 ±8

Eiifieron spp.

2±1

4±1

1± 1

<1

Pragaria vesca

3±2

<1

<1

<1

stands; those most coininon were Galiiini
horeale (northern bedstravv) and Sinilacind
steUata (false Solomon's seal).

Many lor!) speeies oecurred imder the pine
canopy, but they contril)uted little to total
abovegromid biomass. We categorized 22
species as uncommon, using "uncommon" as
we defined it for graminoids. Wrage (1994)
also noted man\ torbs that were generalK'
scarce. If we arbitrarily classify uncouunon
species in Wrage's study as those having <1%
foliar cover in <3 pine co\'er classes over all
years, IS lorb species would l)c (.'ousidercd
unconmion (Wrage 1994: Appendix 1)).

Nine of the forbs found in tlie pine under-
story are exotic species. Only 2, ho\\t\ cr, w cic
common: Turaxannn officinale (common dan-
d(4ion) and Trifoliniii rcpcns. i'hcsc species
are both ubiciiiitons over North America, iwo
others, both noxious weeds, Cirsium ancnsc
(Canada thistle) and C. vulfiare (bull thistle),
were couniion ouK loealK. Aiiodiei', l.iiuirid

iul<!,(iri.s (butter-and-eggs), was found onK in
pole clearcuts. 4'he other 4, Poh/iiomiin pcrsi-
caria (lad\ s thumb), Tr(iii,()i)()^()n diihiits (goats
beard), Sisyinhriuin (illissiiniiiii (tumbling nuis-
tard), and Riiincx aceioseUa (sheep sorrel),
were rare. A large amoimt of Clwnopoditim
capitatiDn (strawberry blite) was found in 1
plot of 1 replicate of sapling CSL 9 m- ha~' in
1976 (Table 2). It is unknown whether this
speeies is indigenous or e.xotic (Great i'lains
Flora Association 198fi). Wrage (1994) listed 4
exotic species. (Ursiiiui (irvcnsc. C.Dninlniliis
(iiTCiisc (field biudwt'ed), Tdraxdcuin o(jiriudh\
and I'rd^opo^on diihiiis. \\\ were classed as
unconnnon except (4)un>lnilii.s diTCiisc. which
was connnou in open stands.

.Although our aboxcground biomass esti-
mates of lorbs wcTi- less than loi' graminoids,
there were moic fori) species than gramiuoid
s|)eeies. I'Hty-lhree forbs. including 15 idenli-
lied ouK to gemis, grew in die uudeislorx'; 25
identified s|H'eies were eonunou to both

1998]

PONDEHOSA PiNI-: UNDKRSTOHV

321

Table 4. Continiu

(Jrowiiig stock k'vcls (m- lia ')

('li'artuts

14

23

Unthiniifcl

Calitmi horcale
Iris inifisoiiriensLs
Lactiua spp.
Latlu/nis oclirolcuciis
Luuiria vulgaris
Oxtjlropis scricca
Poti'iitilla spp.
Soli(I(i<:,o spp.
Taraxacum ojficiiialc
Trifoliiiin rcpen.s
Vicia americana
Viola spp.

1±1

7±(i
<1

<1

3±3
<1
5±5
2±2
5±<1

<1

5 ±2

B + 4

<1
<1

23 ± 23
<1

3 ±2

<1
3±1

9±

<1

<1

8±7

<1

1 ± 1

<1
<1

<1

Total

Sum lis

Ainclaiichicr aliiijolid
Arctostapliylos iiia-iirsi
Berheri.s rcpeiis
Betiila papiihjcra
JunipeniH communis
Popuhis tremuloides
Rosa woodsii
Ruhus idacus
Slwplwrdia canadensis
Spiraea hetulifolia

161 ± 15-'

1±1
209 ± 7

<1
<1

21±21
10 ± 8
49 ±17

1±<1

Sfi ± 35-'''

2S ± 51 '

5±5

<1

305 ± 94

306 ± 72

19 ±19

<1

<1

2±2

10±fi

22 ±7'

135 ± 35

<1

10 ± 10

1±<I

<1'

66 ± 58

<1

Si/mphoricari)os sjip.

7±7

3 ± 3

2±2

2±2

<1

Total

299 ± 48

347 ± 77

311 ±70

149 ±43

67 ± 58

Chand Total

99S ± 84''

626 ± 46' '

387 ± 87l«'

203 ± 341"-

72 ± 58^-

saplings and pole.s. while 6 and 7 species were
nni(|ne to the sapHng and pole understories,
respectixely. Ease (1958) and Wrage (1994)
noted 63 and 41 forb species in their respec-
ti\e stndies.

We found an axcrage of 18 forb species
o\ er all \ ears in clearcut sapling stands, which
was significantK' higher iP < ().()5) than the
15, 13, and 13 species found in GSLs 5, 14,
and 23 ni- ha~', respecti\el\. Ele\en species
were found in unthinned stands, fewer (P <
0.05) than in clearcuts (Uresk and Severson
1989). Trends were similar in pole-sized stands.
Twent\-()ne species were found in clearcuts
and 18 in GSL 5, which was higher (F < 0.05)
than the 12 and 13 found in GSLs 14 and 23.
Fewest species (5) were found in unthinned
pole stands (Uresk and Severson 1989). Wrage
(1994) counted 36, 29, and 24 forbs in Pimis
stands with open, intermediate, and dense
canop\- covers.

Shrub Response

Mean shrub production was similar across
all Finns ponderosa sapling stocking le\els in
1976 and 1981 and in 1974 pole stands. In the
remaining sapling (1974) and pole (1976, 1981)
stands, all growing stock levels produced more
shrul)s than mithinned stands. In general, shrub
production tended to be somewhat higher at
mid-levels than in clearcuts and much higher
than in unthinned stands, although differences
among lower (iSLs were not significant (Tables
1-6). ArctostapJiylos iiva-iirsi accounted for
most shrub production in all stands regardless
of size class or stocking levels, but differences
were not significant except in pole stands in
1981 (Table 6). Production oi' Arctostciplujlos
uva-ursi was 75-99% of total shrub production
in sapling stands and 70-99% in pole stands.
Lower percentages tended to occur in clearcuts.
Higher proportions oi Riilnis idaeiis (red rasp-
beriy) and Syinplioricarpos spp. (snowberry)
were found in clearcuts. Rosa woodsii and

322

Great Basin Natltulist

[\'olume 58

5f d

p ,:i

T3^

-a 1,

a b

S c3

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+1 +1

— -r

+1 +1 +1

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+1 +1 +1 +1
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t-

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+1

+1

+1

^^

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w

V

^-*

1 — '

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+1 +1 +1 +1

CO -H

+1 +1 +1
og cc CO

^ V V

— CI -^ a; x

V "^1 oi lO — ' CO

+1 +1 +1 +1 +1 +1

— Ol O] O <N QC

iO CO X CO

+1 +1

lO t-

+1 +1 ^
o 2 f? V

■r H

•s = a. =0

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& n.

a. K -= Si o

^55

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in

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+1

no

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+1 +1 +1 +1 +1 +1

\r\ t~- -r t X ~

CO

CO

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— 1

10

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+1

+1

+1

+1

+1

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t-

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1998]

PnxnKHosA Pi\i: rxDi-Ksroiiv

323

V S
+1 +1

V J.

+1 +1

V V

_ V

+1 +1

Ol —

V

+1 +1 +1

+1 +1

t^ V

+1 +1

V

c^ — cc I-

+1 +1 +1 +1
w ro ;<; CO

CO oj

+1 +1

-^ t- LO

— fM y:;

+1 +1

-^ CO LO f>] Ol

+1 +1 +1 +1 +1

— I CO ^ CO lO

w V o; oi o) ^
+i +1 +1 +1 +1 +1
^ '^' w iS -r '^i ^

05 — -^
+1 +1 +1

§"' •^ ^ S S V^ -i

^ ^ ^ ri -^ ~^ 1^

324

Great Basin Naturalist

[V'olume 58

Table 6. Underston' procliictioii (kg lia"', ovcn-dricd liasis) for 1981 in pole-sized pondeiosa pine stands growing at
different tree stocking levels, Black Hills, Sonth Dakota. Numbers are means ± standard errors, \alues within a row fol-
lowed by different letters are significantly different at the 0.10 probabilitx le\el.

C'learcnts

Growing

stock levels (m-

ha-i)

5

14

23

L nthinned

ClUMINOIDS

Agropijwn canimtm

41 ±9

26 ± 3

<1

<1

AristUla purpurea

<1

Brouius porteri

2±2

Carex spp.

83 ± 26^

60 ± 23''

7±5'-

14±4'>

<1±<1^-

Danthouia intcnncdia

651 ±95

365 ± 60

95 ±17

30 ± 15

<1

Fi'stuca ovina

17±8

<1

3±3

Koeleria pt/niiiiidcitii

10 ±10

4±2

<1

On/zopsis (isperijitUa

11±8

24 ±13

7±3

15 ± 15

Orijzopsis pung,ens

5±5

2±2

Phlcuin prah'Hse

1±1

PiHi prateiisia

89 ±37

<1

Poa interior

5±1

1±<1

<I

Unknown grass

2±2

<1

<]

<1

Total

916 ±81"

484 ± 63''

1 13 ± 26^

61 ±30"!

4 ± 3^1

FORBS

Achillea millejolium

72 ±18

15 ± 3

5 ± 3

<1

<1

Agoseris glauca

5±4

<1

Antennaria neglecta

23 ± 15

7±7

3±3

3±1

1±<1

Apociinum androsaemijolium

1±<1

5±4

2±2

<1

<1

Astragalus si:)p.

17 ±9

2±1

1±1

<1

Astragalus adsurgeus

4±2

21 ±10

25 ± 13

5±4

Astragalus canadensis

17 ±14

34 ±28

9±9

<1

Astragalus fenellus

5±3

7±6

5 ±5

13 ± 6

Campanula rotundijolia

39 ±8

5±2

2±2

<1

Cirsiuni vulgare

1±1

Delphinium Incolor

<1

Erigeron suhrinervis

10 ±9

<1

<1

<1

Fragaria vesca

12 ±7

7±2

1 ±<1

<1

<1

Riibiis idacus produced nioix' at the 3 lower
saplinj^ GSLs in 1976 (Table 2), while Arc-
tostaphylos iiva-iirsi was more ahimdaut in
pole elearcut.s in 1981 (Table 6). Pa.se (1958)
noted the same patterns of Arctostaphylos
uva-iirsi abundance, but this species did not
occin- in VVraj!;e s (1994) study area. Si/mpliori-
car]H)s occidentalis was the most conunon
shrub noted by Wraj^e (1994) under all Piiuis
canopy levels. Juniperus comfiiuiiis (conunon
juniper), rare on our study site and on VVrage s
(1994), was abundant on sites studied 1)\ Pase
(1958). This species is a pri'dominant con-
stituent of Pinus pondcrosd nnderstor\ on
limestone-derived soils ('i'hileniiis 1972, lioll-
man and Alexander 1987).

I'ourteeu shrub species occurred under the
Piiiiis canopy, 11 of which were common to
both sapling and pole-sized stands. One species,
Vaccinhini scojxininn (tirouseberiA ), was iini(|iic

to sapling stands and was conunon in higher
GSLs (Tables 1-3). None of the shiiib species
under saplings were categorized as uncom-
mon. Three species, all unicjue to pole-sized
stands, were classed as nnconmion: Jiinipcru.s
coiiniiiiiti.s, Bchild papcrijcra dxipi'r birch),
and PoU'iitilld fntticosd (shrnbln cin(iuetoil).
Pase (1958) counted 18 shrub specic-s, while
Wrage (1994) noted only 6.

There were no diflerences (/' < 0.05) in
numi)er of shrub species among sapling GSLs;
they ranged from (i to 8 across all lexcls with
no apparent paltc in. in \)o\c stands S shrub
species occurretl in clearcuts but onl\ 4 species
were foimd in GSL 5 (I'n-sk and Se\ t-rson
1989). VVrage (1994) did not note an\ difler-
ences. lie foimd 4 shrub species nndi'r opi-n,
5 under intermediate, and 5 under dense Pinus
canopies. None ol the shrubs lonnd in the
iMidcrsloiA ol oni- stuck or WVage s were exotic.

1998]

P()\ni:iu)s\ Pink lADKHsroin

325

Tabi.K (i ContiniKM

(-'Ic'lUCtltS

(Irow

ii.U stock lf\ cIs (iii-

ha-')

5

14

23

Untliiimed

i'.dliiiin borcalc

<1

<1

<1

lUtUjsurwn alpiiuiin

<1

Iris iiiissoitrii'n.sis

1±1

I.dtlu/ru.s ochroh'iiciis

57 ±27

48 ± 15

34 ± 13

21±11

2±2

l.iiKirid vulgaris

1±1

Monarddjhtiilo.'ia

<1

l\>l[lil.()nwn pcrsicdrki

<1

liiiiucx ocetosclld

<1

S(>lula>:i> s))arsill(>rd

2±1

4±2

5±2

<1

TdrdXdciiin ofjuiiuilc

2±4

<1

Trifoliitin rcprii.s

91 ±33

15 ±12

\'iri(i dincricdiia

2±2

5±5

7±6

3±2

<1

Viola ddiincd

19 ± 6

12 ±5

<1

<1

<1

lutal

385 ±11"

189 ± 12''

100 ± 8^-

44 ± 15'i

6±3''

SllHl'BS

Atiu'ldiwhicr dliiifolia

1±1

<1

3 ±2

Arctostaphyhis ina-tirsi

11 10 ±102-'

864 ± 144-'l'

673 ±115''

522 ±91''

26±18^-

Bcrhchs rcpciis

34 ± 34

<1

Jiiiiipcnis coiiuiuiui.'i

<1

Papiiliis trcinuhndes

93 ±93

<1

Pninii.s liixiiiiaiid

1±1

Riisd uood.sii

22 ±84

2±2

6 ±3

<1

2±2

Ridjii.s iddcit.s

96 ± 56

36 ±12

Slu'i)hi'rdid cdiiddeusi.s

215 ±148

7 ± 7

Spiraea hctidifolia

5± <1

3 ± < 1

6±1

2±<1

1±<1

Syinphoricarpos spp.

16 ±11

4±1

8±5

3±2

3±1

Ibtal

1344 ± 43''

945 ± 116''l'

910 ±144^1'

535 ± 97''

31 ± 19'

ClRAM) Total

2644 ± 35-'

1620 ± 86''

1 123 ± 132''

640 ±112^

41±21<'

Total Understory Response

Total understoiy production was variable
among GSLs; but, generalU', the greatest
amounts in sapling stands were produced at
GSL 23 m- ha~' or less and in pole stands at
GSL 14 m- ha~^ or less. Unthinned stands
consistentK produced significautK' less forage
than all other GSLs (Tables 1-6). The same
trend was noted by Pase (1958).

We identified 89 species in the Pimts pon-
dcrosa understoi-\' over all stocking le\ els and
tree size classes. An additional 19 plants were
identified onK" to genus, and 6 others were
designated as unknowns. Pase (1958), who sam-
pled a greater \'ariet>' of sites, found a total of
119, while Wrage (1994) tallied 70. Hoffman
and Alexander (1987) sampled 10 stands in the
Piniis pondcrosa/Arctostaphyln.s uva-ursi habi-
tat t\pe and found the range of the total num-
ber of species to be 13-29. Uresk and Sever-

son (1989) found more species (P < 0.05) in
sapling and pole clearcuts (34 and 40, respec-
ti\ el\ ) than in mid-level GSLs (saplings 27-28,
poles 22-24). Fewest species were found in
unthinned stands (23 in sapling and 12 in pole
stands). The only species occurring regular!)'
in unthinned stands were Onjzopsis aspcifo-
lia, Danthonia intermedia. Lathy nis ochroleu-
ciis, dudArctostapJiylos uva-nrsi (Tables 1-6).

Conclusions and Man.agement
Implications

Piuiis pondcrosa is the most abuudant and
wideK distributed tree in the Black Hills. It is
the major climax tree species in 7 of 12 forested
habitat types described by HoflFman and Alex-
ander (1987) and a serai or occasional species
in 2 others. The climax stands occupy about
600,000 ha (Boldt et al. 1983). Natural regen-
eration of Pinus ponderosa in the Black Hills is

326

GRE.vr Basin Naturalist

[\blume 58

aggressive and prompt, with liigh stand densi-
ties often resulting (Boldt and V'an Diiesen
1974, Hoffman and Alexander 1987). There-
fore, Pinits ponderosa often replaces itself when
tlie stand is disturbed. Only 2 of 7 Pinus pon-
derosa habitat types have potential serai stages
dominated b\' Popidus trcinidoides. Quercus
macrocarpa (bin" oak) is a minor serai species
on another (Hoffman and Alexander 1987).
Exidencc indicates that eliminating or reduc-
ing the Pinii.s ponderosa overston' will increase
the number and total productivity' of under-
story species. This has 2 apparent advantages.

First, and most obvious, is that such a reduc-
tion is a viable approach to increasing plant
species richness of the Black Hills. The habitat
t\pe we studied, Piniis ponderosa/ Arctostaphij-
los iiva-iirsi, is not the most floristically rich.
We could expect even more dramatic responses
to occur in those habitat types that have more
species (e.g., Piniis ponderosa/Qtierciis macro-
carpa habitat type; Hoffman and Alexander
1987: Table 4). Hence, each F//]».s-dominated
habitat t>'pe would likely have a unique under-
story response to canopy changes. Eliminating
Piniis overstory in those habitat types where
serai stages are dominated by aspen would
create an even more diverse community struc-
ture. Peripheral evidence suggests that aspen-
dominated stands contain more species than
Pinus or mixed Popidus trcmidoides-Piniis pon-
derosa (aspen-pine) stands (Kranz and Linder
1973).

Second, a floristicalK' rich and productixe
understor\' would support a healthier popula-
tion of herbivores. Ruminants can select nutri-
tious diets from a diverse arra\ of plant species
(Proxen/.a 1995). Odocoileus virginianus (white-
tailed deer), for example, have the abilit) to
select a \ ariet>' of forages that collcctiveh' bal-
ance nutritional needs (V^angilder et al. 1982).
lU'ducing the number of plant species and the
resulting decline in selectixc feeding ability
would also increase comiietilix c iiiterattioiis
among herbi\'ores.

.Several exotic species occui in the riniis
understory. Some, such as Taraxaciiin otticinalc
and Trifoliwn repciis, an- ubi(|uilous within nat-
ural systems. Others, like ('irsiinn vul<i,(iri\ ('.
arvense, and Convolvulus arvcnsc, are desig-
nated noxious weeds and niusf be controlled
by law. Although they ma\ be loc alK toiiiinoii,
their distribiilion w illiiii /'/////.s-doiiiinatcd com-

munities is limited. Other exotic species appear
to be uncommon and restricted to disturbed
sites in open areas, such as skid areas on clear-
cuts. The presence and distribution of exotic
species should be a part of monitoring actixities.

A similar status is afforded threatened, en-
dangered, and sensiti\e plant species in the
Pinus ponderosa underston-. None of die species
found in this study or Wrage's (1994) is listed
as sensitive in the Black Hills (Fertig 1993).
Most listed species are found in mesic habi-
tats, but this should not preclude a more
intensive survey o( Pinus understor\.

Most evidence provided herein represents
a case for maintaining Pinus ponderosa stands
at a range of stocking lexels. While floristic
species richness is greater on clearcuts than in
unthinned stands, the total number of plant
species would be greater if both clearcut and
unthinned stands were present. Species such
as Linnaea borealis (twinflower), Shepherdia
canadensis (buffaloberrv'), and Vaccinium sco-
pariutn (grousebern) are more common under
relati\'el\' dense Pinus canopies. From an eco-
nomic standpoint, clearcuts and ver\' low
Pinus stocking levels promote more growth of
a\'ailable forage for lixestock, w hile intermedi-
ate stocking levels produce more wood fiber
(Severson and Boldt 1977). Wild ungulates
need open areas for foraging and dense conifer
stands for cover; intermediate stocking le\els
provide only marginal le\els of both (Sieg and
Severson 1996).

Historical e\ idence shows that patterns ol
biotic comnnmitx de\ t'lopnient in the lilack
Hills prior to Euro-American inti'rxention wei'c
more heterogeneous than those found toda\,
piimaiiK due to the influiMici' of fire (('.raxes
1899, Progulske 1974, Turchen and McEaird
1975; see also USDA Forest Si-rx ice 199 1,
Sieg and Sex-erson 1996), although a lew large.
dense Pinus stands did exist (Ciraxes 1899). We
exanuned ouK influences of mt>chanical tree
reiiioxal; the inclusion ol [irescribed lire xxould
liaxc pioduced dilfi-ri-nt results (Sieg and Sex -
crson I99(i). Eittei- remoxal 1)\ burning would
stimulate a fasti'r iindcistorx ri'sponse (due to
exi)osm(.' of miueial soil and rapid nutrient
release). ,'\ different species response in the
understorx could also be expected. I'or cxain-
ple, nonsprouting species would be li'ss abun-
dant and sprouting species relatixi'K more
abinidanl. Other species, such as I'.pilohiiiiii

1998]

PONDKHOSA PiM: UxOKKSR )KV

327

(in<:,u.stif()liuin iHvcwvvil). cliaiacft'risticalK
iinadc hiinit'd sites ((iivat Plains Mora Asso-
ciation iy8(-)).

A serious apiHoaeli to (.'cosystcni nianaiir-
nuMit, inclndinti concern tor health and niain-
tiMiance of natural s\stenis and economic and
social needs, should consider all habitat types
and all serai stages within those habitat types.
Special attention must be gi\en to placing these
in optimum spatial and temporal mosaics.
Such mosaics would include the presence of
relati\ el\ large, dense Pinii.s stands w hich were
present in the Black Hills prioi" to this centin-\
(Gra\es 1(S99). The historical pattern of fire-
induced communit>' dexelopment, coupled with
patterns of species responses to overstor\' re-
duction, indicates that planning for a higher
le\('l of landscape di\ersit\' would be a logical
approach for ecosxstem management in the
lilack Hills. Howexer, specific goals, under
current social and economic constraints,
would likeK dictate a landscape that differs
from one shaped entircK 1)\ natural forces.

LiTEHATURi': Cited

15F.NNETT, D.L. 19S4. Gnizing potentiiil of major soils with-
in the Black Hills of South Dakota. Unpublished
master's thesis. South Dakota State University,
Brookings.

BoLDT, C.E., R.R. .ALii.vwDKH, AND M.J. Larson. 1983.
Interior ponderosa pine in the Black Hills. Pages
80-8.3 in R.M. Bums, technical compiler. Silvicul-
ture systems for the major forest types of the United
States'. USDA Forest Sei-vice Handbook 445. USDA,
Washington, DC".

BoLDT, C.E., .\ND J.L. \'\\ Di r.SFN. 1974. Silviculture of
ponderosa pine in the Black Hills: the status of our
knowledge. Research Paper RM-I24. USDA, Forest
Service, Rockv Mountain Forest and Range E.xperi-
ment Station. Fort Collins, CO.

DlNNETT, C.VV. 1980. Pairvvise multiple comparisons in
the unequal variance case. Joinnal of the American
Statistical Association 7.5(372j:79(>-80().

Fertk;, \V. 1993. Black Hills .National Forest sensitive
plant field guide. USD.V Forest Service, Region 2,
Black Hills National Forest, Custer, SD.

Ffoli.IOT, PF, and W'.P Clarv. 1982. Understor\-over-
stor\- vegetation relationships; an annotated bibliog-
raphy. General Technical Report I NT- 136. USDA,
Forest Service, Intermountain Forest and Range
E.xperiment Station, Ogden, UT.

Gr.wes, Henry S. 1899. Black Hills Forest Reserve.
.Annual report. U.S. Geological Survey 19:67-164.

Gre.\t Pl.\ins Flora Associ.\tion. 1986. Flora of the
Great Plains. Universitv- Press of Kansas, Lawrence.

HOFF\i.\N, G.R., AND R.R. Ale.v\nder. 1987. Forest vege-
tation of the Black Hills National Forest of South

Dakota and Wyoming: a habitat type classification.
Hescarcli Paper HM-276. USDA, Forest Senice,
Rock^ Mountain Forest and Range E.xperiment Sta-
tion, Fort Collins, CO.

K\i fmann, M.R., ET Al.. 1994. An ecological basis for
ecosystem management. General Technical Report
RM-246. USD.A, Forest Service, Rock^ Mountain For-
est and Range tlxperiment Station, F'ort (Collins, Q.O.

KlUNZ, J.J., AND R.L. Lender. 1973. Value of Black Hills
forest conununities to deer and cattli'. Jouriial of
Range Management 26:26.3-26.5.

Pasi;. (^P 19.58. Herbage production and composition
under immature ponderosa pine stands in the Black
Hills. Journal of Range Management 11:238-243.

l'H()(;i'ESKE, D.R. 1974. Yellow ore, yellow hair, yellow
pine. A photographic studv' of a centurv of forest
ecology. Agricultural F>xperiment Station Bulletin
616. South Dakota State University, Brookings.

Pro\ENZ.\, V.D. 1995. Postingestive feedl)ack as an clcmen-
tarv' determinant of food preference and intake in
nuninants. Joimial of Range .Management 48:2-17.

Sfvfrson, K.E., and C.E. Boldt. 1977. Options for Black
Hills forest owners: timber, forage, or both. Range-
man's Journal 4:13—15.

SiEc;, C.H., AND K.E. Severson. 1996. .Managing habitats
for white-tailed deer in the Black Hills and Bear
Lodge Mountains, South Dakota and Wyoming: a
review. General Technical Report RM-274. USDA,
Forest Service, Rockv Mountain Forest and Range
E.xperiment Station, Fort Collins, CO.

Thilenius, J.F 1972. Classification of deer habitat in the
ponderosa pine forest of the Black Hills, South
Dakota. Research Paper R.\I-91. USDA, Forest Ser-
vice, Rock^' Mountain Forest and Range Experiment
Station, Fort Collins, CO.

Tl rcuen, L.\', and J.D. McLaird. 1975. The Black Hills
Expedition of 1875. Dakota VVesleyan University
Press, Mitchell, SD. 126 pp.

Uresk, D.W., AND K.E. Severson. 1989. Underston -o\ er-
storv' relationships in ponderosa pine forests, Black
Hills, South Dakota. Jomnial of Range Management
42:20,3-208.

USD.A Forest Ser\ ice. 1994. The range of natural vari-
ability for the Black Hills: a first step. .Appendix A.
Pages 1-98 in Draft environmental impact state-
ment. USDA, Forest Senice, Black Hills National
Forest, Custer, SD.

\'an Brl'(;gen, T. 1985. The vascular plants of South
Dakota. 2nd edition. Iowa State University Press,
Ames.

\angilder, L.D., O. Torgerson, and W'.R. Porath. 1982.
Factors influencing diet selection b\' white-tailed
deer. Joiniial oi Wildlife .Management 46:71 1-718.

\\r.\GE, K.J. 1994. The efl'ects of ponderosa pine (Pinus
ponderosa Laws.) on soil moisture, precipitation, and
understorv' vegetation in the Black Hills of South
Dakota. Unpublished master's thesis. University of
South Dakota. Xennillioii.

Received 21 October 1996
Accepted 27 September 1997

Great Basin Xatiiralist 58(4), © 1998, pp. 328-343

BIRD USE OF RIPARIAN VEGETATION ALONG
THE TRUCKEE RIVER, CALIFORNIA AND NEVADA

Snellen L\nii^ Michael L. Morrison ^■-. Ann J. Knenzi', jeiuiiler C.C. Neale\
Benjamin N. Sacks\ Robin Ihnnlin', and I.innea S. Hall' -

Abstract. — Tlie Truckcc Hi\er in California and Nevada is subject to di\erse water regimes and a corresponding
varietA' of flow rates. Original riparian vegetation has been altered by these variable flow rates and by a \ariet> of human
uses resulting in loss of native riparian vegetation from its historic extent. We conducted bird surveys along the Tnickee
River during spring 1993 to (1) determine relationships between birds and the present vegetation; (2) detemiine the
importance of different vegetation types to sensitive bird species that have declined recentlv" in the vvesteni United
States due to competition from exotic plant species, cowbird {Molothru.s ater) parasitism, reduction in nesting habitat, or
other unidentified reasons; and (3) establish a monitoring program and collect baseline data for future comparisons. The
most frequently detected bird species throughout the study was the Brown-headed Cowbird. The greatest number of
bird species (98 of 116) was found in the native mixed willow [Salix spp.) riparian scrub vegetation t>pe. We recommend
protecting the remaining native riparian vegetation types for bird habitat along the Tnickee Riv er

Key wordx: bird abundance, bird species richness, riparian habitat. Tnickee River, vegetation type.

Numbers of Neotropical migratoiy birds are
declining throughout North America (Martin
and Finch 1996). Explanations for this decline
include reduction and fragmentation of lireed-
ing, wintering, and migratory stopox er habitat
(Stevens et al. 1977, Finch 1991a). Riparian cor-
ridors are well-known breeding and migratory
stopover sites for manv Neotropical migrants
(Bottorff 1974, Stevens et al. 1977, Wauer 1977,
Szaro and Jakle 1985). These corridors aie
important as cover and foraging habitat for
birds migrating through sparseK' \egetated
desert areas (Sprunt 1975, Stevens et al. 1977).
Historically, such corridors existed along the
Truckee River and its tributaries in northeast
Calilornia and northwest Nevada (Ridgway
1877, Kicbenow and ( )akleaf 1984).

At present the native riparian vegetation
along the Truckee River is greatly reduced Iroui
its historical extent (Klebenow and Oaklcal
1984, USFVVS 199;3). A number of ficlors have
contributed, and continue to conlribulc, to llic
reduction in riparian vegetation since the late
18()()s, including varied How rates from diver-
sions ol water lor agricultural use, channeli/a-
lioii ol |)aits ol the livci' in tlic caiK 19(i()s, log-

ging, gravel removal, and grazing (Klebenow
and Oakleaf 1984). Consequently, the Truckee
River riparian corridor is now a thin, discon-
tinuous ribbon of cottonwoods {Populiis spp.)
and willows {Salix spp.; USFWS 1993) ranging
up to 250 m wide, but averaging approxi-
mately 3()-5() m wide where present.

CiurentK, there are no baseline data relat-
ing bird populations to xegetative conunuui-
ties along the Truckee River. Our studv was
designed in cooperation with the U.S. Fish and
Wildlife Service (USFWS) to establish a svs-
tematic sampling scheme for monitoring bird
numbers and species composition along the
Truckee River, and to obtain (iuantitati\e base-
line data on bird-vegetation relationships to
satisfy the I'Si'WS operating plan for the
Truckee Hivi'i-. Our specific objectives were to
determine (1) bird species composition and
relative abimdances of biids in the major veg-
etation t\ i)es, (2) bird specii's most likeh to be
impacted bv alterations ol the native riparian
plant coniinnnities, and (3) vegetative compo-
nents (successional stage and species composi-
tion) that contribute most to bird abuntlance
and species richness.

'School of RciK-wablc \,.lm.il Hcmmikcs. Wildlilc and I'Isluii.s Scii-mis I'touniin, l'iii\.Tsil\ nl Ari/i.fia, luiNoii, A/ .S,5721,
2Pri-sciil address: ncpartiiu-nt iit liioldnlial Sciences. Calilornia State I'niversity. Sacramento. (.AU.Wiy.
■'Deparlnient ol Knvironniental Sciincc. I'oliev. and Management, I'niversitv of California. Berkc'ley. C.\ 91720.
■'U.S. Hsli Mild Wildlife Senile l(i(K) Keil/ke Lane, Hiiildini; ( I- 12.5. Rem), \V H9.'5()2.

328

1998]

Bird Usk of Hii'akiw Vkcetation

329

Sti'dy Arkas

\\(.' coiitluctc'd our stucK alonj; the Irutkcc
Hi\t"r, California and Nevada (approximately
SO km), and the Little Tnieke(> River (16 km)
and Independence Creek (3.5 km), C>alif()rnia
(Fig. 1). We divided the Truckee River into
"lower" (Pxramid Lake to Sparks, Ne\'ada) and
"upper (Floriston, Nevada, to Lake Tahoe)

.sections based on the approximate elevational
border where Fremont cottonwood [Poptihis
fn'tnontii) changes to higher-elevation black
cottonwood (P. trichocarf)a- USFVVS 1993).

Vegetation along the lower Trnckei' Ri\er is
eharacteri/ed i)\ a narrow but e.\tensi\'e strip
of willow {Salix spp.), intermixed with occa-
sional clumps of variousK aged Fremont cot-
tonwoods. Agricultural de\'elopment, wide-

10 0 10 20 KILOMETERS

Fig. 1. Map of study site; Tnickee River, California and Nevada: and Little Truckee River and Independence Creek,
California.

330

Great Basin Natlr.\list

[N'olume 58

spread along most sections of the lower Truc-
kee, is especially prevalent near the conflu-
ence of the Truckee River with Pyramid Lake
Reservoir; cattle grazing also is common near
this confluence. Hillsides bordering the ripar-
ian corridor are dominated by upland shrubs
(primarih' shadscale [Atriplex confertifolia] and
black greasewood [Sarcobatiis venniciilatiis]).
Exotic whitetop (or peppergrass [Cardaria
draba]) dominates open, disturbed sites.

Vegetation along the upper Truckee River
is also characterized by a narrow strip of wil-
low-cottonwood association. Black cottonwood
replaces Fremont cottonwood between 1800
and 2150 m elevation. Uplands are dominated
by big sagebrush {Aiiemisia tridcntata). Ripar-
ian vegetation, and especially black cotton-
woods, becomes less dense with increasing
elevation. Extensive stands of mi.xed conifer
forest reach the riverbanks and dominate the
vegetation at higher elevations (1800-2750 m).
Vegetation along the Little Truckee and Inde-
pendence Creek resembles the upper Truckee
River, except the riparian zones along the 2
smaller ri\'ers are dominated b)' willow-alder
{Ainus tenuifolia) and riparian scrub, charac-
terized by willow thickets (Appendix).

Methods

We conducted a preliminar)' stud) during
the fall of 1992 to locate appropriate study
areas and determine the latter extent of the
breeding season of locally breeding birds.
Observers walked various stretches of the
Truckee River and recorded the presence and
freqiiencies of bird species encountered.

louring April-JuK 1993 we sampled birds
using the \ aiiable circular-plot method (l{ali)li
et al. 1993, .Murray and Stauflci- 1995). We
established evenly sjiaced points along tran-
sects (i-le\'nolds et al. 1980) which were dis-
tributed systematicalK along the Truckee River
in a manner that roughly corresponds to the
river stretches used by the USf'VVS for \cge-
tati(m ty])ing (USI-'WS 1993). Wgetation types
were idenlilied and (luaiililied by measure-
ments of percent cover on 1992 aerial i)li()-
tographs (Appendix, Table 1; L'SI<^WS 1993).
Vegetation maps were verified by field obser-
\ations; Ncgetatioii t\pcs were homogeneous
and well defined.

Within each i"i\(.'i' stretch we placed tian-
sects in vegetation t\pes roiigliK propoitioiial

to their occurrence, ensuring adequate repre-
sentation of the patchy, scattered willow and
cottonwood vegetation tvpes. Because the ripar-
ian vegetation is patchy and thin, most sui"vey
points sampled > 1 \ egetation t\ pe. Transects
were also distributed along Little Truckee River
and Independence Creek. Although transects
on Little Truckee and Independence Creek
were established to bisect riparian vegetation,
aerial photos were not axailable for these
streams and so vegetation was not quantified.

The beginning of each transect was ran-
doniK' determined. We established fi.xed points
200 m apart along each transect, which ran
parallel to, and within 10 m of, the stream and
within or adjacent to the riparian corridor.
Channelization of the river determined that
the transects \\'ould be linear, ensuring that
points were >200 m apart. Although the nmn-
ber of points varied among transects due to
differences in the extent of riparian vegetation
and accessibility of riverbank, all transects had
at least 8 points. We sur\'e\ed a total of 250
points as follows: lower Truckee, 136; upper
Truckee, 51; Little Truckee, 45; and Indepen-
dence Creek, 18.

We siuA'cxed along the lowt'r Truckee first
because die breeding season began earlier theie
relati\'e to the other areas (M.L. Morrison,
unpublished field notes. 1992). While this uui\
have confounded our results because we in-
cluded migrants, only 5 species that we de-
tected were not common breeders in the area
(Ring-billed (iull, Calii()niia Cull, Bkick-chinned
Hummingbird, Yellow -breasted (^lat, and Blue
(Grosbeak; scientific names in Table 2). Ihese
species wt'ie all detected in appropriate breed-
ing habitat and ma> ha\e been residents, but
the\ wfre rareh' detected and had little imp;i(.t
on our conclusions, in addition, all ol these
speeii'S except Ring-billed Cull ha\e brccl in
this area historii-alI\ (l\idgwa\ 1877) and theri'-
fore were potential breedeis during our slucK.

All points wcic sam|)li'd 3 tinu's, with t'aeii
transect sur\c'\ t'd forward tw iee and backward
once. W'e completed a round of surxcys on
each transect before begiiniing a new round.
Snrxeys in the lowei' Tiniki'i' wi're conducted
fioni mid- Apiil to Jinie by 2 obserxers, and in
tile other areas fioni June to earl\ July b\ 2
different ol)ser\ers. Willi the exception of one
i.~)-poinl transect counted l)\ tlic same ol)seiX('i'
all .') limes, each tr;msecl x\as suixcxi'd b\ 2

1998]

Bird UsI': oi- I^ii'mu \\ \'i:(;i:ivii()\

331

Tahi i: 1. I'lTccnt c()\iT ol iiiajoi' xctictation txpcs aldiiii tlic Iouct. upper, and dmt.iII TnKki'c l{i\i'r. and ninnljiT of
liirds ohsened, expected, and tlie differeiiee (Ironi X~ aiiaK sis), Truckee River, Calilbmia and Nevada (USFVV'S 1993).

Percent c()\er

N'lnnber of birds-

Ni'iietatioii t\pe

Lowi'r

Lpper

Overall

Observed

Ivxpecled

Dillerenee

Open water

l{i\ciini'

12

25

18

1)

—

—

I'onds

1

<1

<1

—

—

—

lori'st

Siena niixi-d loiiiler'

0

3

2

636

391

-230

Blaek eottonwood''

0

7

4

219

521

-302

IVeniont eottonwood-w illow'

S

3

6

2018

782

+ 1236

Siniih

Alder-willow

0

12

6

43

782

-739

Riparian sernh-niixed willowf^

12

7

10

3011

1303

+ 1708

Marsh

3

3

3

161

391

-230

(;ra\el bars

10

3

7

56

912

-856

Saije steppe

16

6

10

1033

1303

-270

Wliitetop 'peppergrass)

14

6

10

381

1303

-922

A'4rieiilture

23

14

18

—

—

—

"Based on 7558 obsenations; docs not include Little Trnckic \\\\vr or Inclependeiicc Creek ulisenati'

''Not quantified for these \ei;etatioii types/areas.

^Includes lodKcpole pine, JclTrcx' pine, and mixed conifer forest.

''Includes seedling, [xjlc-saplinf;, and mature stages of black cottonwood.

•Includes seedling, pole-sapling, and mature Kremont c-ottouwood. uilli and uitliuut uhitelop.

'includes riparian scrub with and without \\hilrti>p

different obseiAer.s ox cr the .season to standard-
ize obser\er bias (Verner 1985). All observers
were trained b>- 1 technieian and tested against
eaeh other to minimize inter-observer bias.
Before performing a count, each crew member
was tested on a practice count where at least
9()9f of all detections were identical between
trainer and trainee. Species identification and
distance estimations were checked across ob-
ser\ers 1)\ informal testing throughout the
sampling season. The paces of each observer
\\eie measured b\' walking 50 m for 3 replica-
tions at iionnal speed. Distance estimations
wcit' checked b\ pacing to stationar\' objects
tliroughout the .season (Ralph et al. 1993).

We counted birds at each point tor 5 inin.
All counts were conducted within the first 4 h
alter simrise and only on days without precipi-
tation or significant wind. Before beginning a
count, the obsener waited for 1 min to allow
possibK disturbed birds to resume their nor-
mal beiiaxiors (Min-ra\- and Stauffer 1995). All
birds seen or heard at eaeh point were re-
corded. We also recorded the vegetation type
in which each bird was located (Appendi.x),
detection mode (visual, song, call), and dis-
tance from the point to the bird. Before begin-
ning an\ sur\e\', each obserxer was shown
examples of all xegetation t\'pes, which were
distinct and easily identifiable. Therefore, we
could locate the birds precisely and accurate!)

enough to confidentK associate them with
vegetation types when the \ egetation could be
seen. When it could not be seen during a
count, obserxers sought out and identified the
vegetation after the 5-min count.

We analyzed our data to obtain an index of
abundance (mean number of birds/point/coimt;
Raphael 1987) and frequency of occurrence
(percentage of points at which a species was
detected; Verner 1985) for each species dis-
cussed. Because we had small sample sizes of
individual species in each vegetation type, and
distances to birds are often difficult to estimate
(Verner 1985), we included all detections,
regardless of distance from observer, in our
abundance anaKsis (Blondel et al. 1981, Sliwa
and Sherr\' 1992). We also analyzed our data
to obtain distribution of birds by vegetation
t) pe, highlighting bird species richness within
\egctation t\ pes and distribution of species
among vegetation types.

To test the validitx of comparing bird de-
tections among vegetation types, we examined
the relationship among major xegetation txpes
and the distribution of detections of birds by
chstance from the point center using chi-square
analysis. This anal\ sis tested whether detect-
abilitx' (measured In average detection distance)
of bird species varied among vegetation t\'pes.
Had they differed, comparisons of bird abun-
dance between vegetation types would have

332

Great Basin Naturalist

[Volume 58

TAhLE 2. Index of ahundance'' (x) and frecjnency of occurrence'' {%) of birds aloni^ tlie lower Tnickee, upper 'Iruckee,
and Little Tnickee rivers and Independence Creek, Nevada and California, si^riiiji 1993. Species of special interest are
identified with superscripts'.

Independence

Lower Truckee'^' Upper Truckee'' Little Tnickee' Creek*^
Species

(Scientific name'') .v s 7( x s 9f x s ^( x s 9c

American White Pelican 8.3 5.7 3 — ' — — _ _ _ _ _ _

(Felecaniis enjthrorlu/nchos)
Double-crested Cormorant 0.4 0.1 5 — — — — — — — — —

(Plialacrocorax auritus)
Great Blue Heron 0.4 0.1 2 _ _ _ 0.3 0.0 1 _ _ _

(Ardea herodias)
Snowv- Egret 0.5 0.3 2 — — — — — — ___

(Earetta thula)
Black-crowned Night-Heron 0.3 0.0 1 ___ ___ ___

{Nycticorax nycticorax)

White-faced Ibis 1.7 0.0 1 _ _ _ _ _ _ _ _ _

{Plegadis chihi)
Canada Goose 2.5 3.3 15 1.7 0.0 1 0.3 0.0 2 _ _ _

[Branta canadensis)
Wood Duck 0.6 0.3 6 _ _ _ _ _ _ _ _ _

{Aix sponsa)
Mallard 0.9 0.5 22 1.4 2.0 3 0.3 0.0 1 _ _ _

{Anas platyrhynchos)
Northern Pintail _ _ _ 0.3 0.0 1 _ _ _ _ _ _

{Anas acuta)

Cinnamon Teal 0.7 0.3 3 — — — — — — — — —

{Anas cijanoptera)
Gadwall " 0.7 0.3 2 ___ ___ ___

{Anus strepera)
Unknown duck 0.9 0.8 5 ___ ___ ___

Common Merganser 0.8 0.4 6 0.4 0.2 8 1.2 1.3 10 0.3 0.0 2

(Merfius merganser)
Turkey Vulture 4.2 7.H 2 _ _ _ 1.1 0.7 2 _ _ _

{Cathartes aura)

Osprey 0.3 0.0 1 _ _ _ 0.3 0.0 1 0.3 0.0 2

{I'andiiin haliaetiis)
Red-tailed Hawk 0.4 0.2 7 _ _ _ 0.4 0.2 3 _ _ _

{Hutco jainaicensvi)
Golden Kagle 0.3 0.0 1 ___ ___ ___

(Aguda chrysactos)
American Kestrel 0.5 0.2 10 — — — — — — — — —

{Falco sparverius)
California Quail 0.6 0.3 16 _ _ _ 1.4 1.2 6 _ _ _

{('allipepla calijornira)

American C^oot 0.7 0.6 3 — — — — — — — — —

(htlica atncricana)
Killdcer 0.6 0.3 15 _ _ _ 0.3 0.0 1 _ _ _

(C'liaradrius locijcrus)
American Avocet 1.8 1.2 1 — — — — — — — — —

{liccun irostra anicricaiut )
Spotted Sandpiper 0.4 0.2 9 0.8 0.6 20 0.6 0.3 21 0.3 0.0 2

{Actilis iiuicularia)
l^Mig-billed Curlew 0.3 0.0 1 ___ ___ ___

(Numenius ainfricanu.s)

Common Snipe 0.3 0.0 1 — — — — — — — — —

{(^ullinagd gallinago)
Ring-billed Cull 2.1 2.6 I ___ ___ ___

( Lani.s dclaivarensis)

1998] BiKO UsK OF Kii>AHi AN \i:(:i:t\ti()\ 333

Tabli", 2. C^oiitiiiin'il.

Spi'tifs

(Stii'iitilif iKiiiK''')

liKlepenclfnce
Lowi'i TriKki't''^' I'l^iK-r IVuckc-i''' Littlt- TiiKkt'L'' Cit'i-k*^

C:alif'oniia(;ull'^ii 0.7 0.5

{I Aims cdlifoniicii.s)
UnkiiDwii iiiill
Kock D()\e

(Coluinha livia)
Baiul-taik'd Pigeon

{Columbii jasciata)
Moiiriiiiii; Dove
Ziiiiiidd inacroiira)

C.reat llonud ( )\\1

[Bubo vir<iiniaiiiis I
Black-cliimu'd I limiiniiiuhircl

(AitIuIocIiii.s alcxandri)
C-alliope I Iiiiniiiiiinbird

^Stilhtld calliope)
Hcltrd Kiiiiit'i.sher

iCcrylc (ilcijon)
Hrd-hreasted Sapsiicker

( Siiliympicu.s ruber)

\\'illiains()n s Saii.siicker

' Siiliyrapirus thijroideiiii)
Dow n\ Woodpecker

( Picoides piibesceiis)
Hain Wbodi^eeker^"

iPicoide.s lillo.sii.s)
W'liite-lieaded Woodpecker

I Picoides albolanatus )
Black-backed Woodpecker
Picoides arcticiis)

Nortlierii l-"licker

iX'olaptes uuratus)
()li\e-sided Fl\ catcher^

'Contopits borealis)
Western Wood-Pewee

' Cant opus sordiduhis)
W illowFl\ catcher* ''

( Empidonax trailii)
Hammond s F-'Kcatcher 0.3 0.1 1 —

{Empidonax luiiinnoiidii)

Dnsky FK catcher 0.3 0.1 2 —

I F^inpidonax oberholseri)
Empidonax .species 0.4 0.2 3 0.3 0.5

Sa\ s Phoebe

0.4

0.2

3

0.3

0.1

1

0.7

0.5

IS

0.4

0.2

1

4.1
1.2

(i.S
1.3

12
4

0.4

0.2

3

—

—

—

—

—

—

0.3

0.0

1

—

—

—

—

—

—

0.7

0.4

19

0.7

0.0

1

0.3

0.0

1

—

—

—

0.5

0.2

1

—

—

—

—

—

—

—

—

—

0.7

0.0

1

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

0.0

0.4

2

0.5

0.2

4

0.4

0.2

3

0.4

0.2

2

0.3

0.0

2

—

—

—

—

—

—

0.3

0.0

1

0.5

0.3

4

0.4

0.2

8

—

—

—

—

—

—

0.5

0.2

2

0.3

0.0

2

0.5

0.2

3

0.4

0.2

3

0.3

0.0

1

—

—

—

—

—

—

0.3

0.0

1

0.3

0.0

1

0.0

0.5

8

—

—

—

0.5

0.2

1

0.3

0.0

1

0.3

0.0

2

0.5

0.3

3

0.4

0.1

9

0.5

0.3

12

0.4

0.2

4

0.3

0.0

I

0.4

0.1

7

0.3

0.0

1

0.3

0.4

4

0.5

0.3

8

1.2

0.7

23

1.3

0.5

31

1.5

1.0

36

0.3

0.0

I

0.5

0,2

1

0.8

0.4

32

0.5

0.3

10

0.0

0.2

28

fSatjoruis saya)
Western Kingbird

( Tyraiiiuis vertiealis)
Tree Swallow^ H-^:b 0 4 02 l l.i 1.0 6 — — — 0.3 0.0

( Tachycineta bicolor)

\iolet-C;reeii Swallow^O *:» 0.3 0.0 1 _ _ _ 0.3 0.0 1 —

I Tachycineta thalassina)
Northern Roueh-winged
Swallow 0.9 0.9 22 _ _ _ 4.3 2.6 5 —

{Stclgidoj)teryx serripenids )
Bank Swallow"^" O.S 0.5 5 — — — ___ —

{Riparia riparia)

334

Cheat Basin Naturalist

[N'olunie 58

Table 2. Contiiuiccl.

Species

(Scientific name'^)

Lower Triickee''

Upi^er Triickee"' Little IVirIni

Inclcpendence
Creeks

.V .V '^c

Clifl'SwalKm

illirundo pijirhonota)
Barn Swallow

(Hiriiiulo rustica)
Unknown .sv\'allow
Steller's Jay

[Cyanocitta stelleri)
Clark s Nutcracker

{Nticifni^a cohiiiihiaiia)

Black-hilled Magpie

(Pica pica)
American Crow

(Cortu.v hracliijrhijnclios)
Common Raven

(CorviLs corax)
Moinitain C]liickadee

iPani.s '^ainJieU)
Busiitit

il'saltripanis ininiinits)

Red-breasted Nnthatch

iSitta canadensis)
Wliite-Iireasted Nnthatch

(Sittd carolinensis)
Pygnn Nnthatch

(Sitta pij^tnaca)
Brown Creeper

(Cciili id aincricana)
Rock Wren

iSalpinctcs ohsoh'tus)

Bewick's Wren

( Thnjotnaiies hcuickii)
House Wren

( Trofilodijtc's aedon )
Marsh V\'ren<-B'^"

iCistoOiorus palustris)
American Dipper

(Cinclus tnexicamis)
Ruhy-crowned Kingk't

{Reiiulus calendula )

Blue-Cray (inalcatciic r

il'olioptila cacrulca)
Mountain Bluebird

iSialia curnicoides)
Townsend's Solitaire

(Mijadcslcs ((Hcnscndi)
liennit Thrnsli

(('atliartis nullutu.s)
American Robin

(Tiirdiis niiui'aloi'iiis)

(iedar W'axw ing

(lionihijcilla ccdnirnin >
l\uro])ean Starlinn'"^

iStiintits nil'iaris)
Solitaiy Vireo

(Vireo s()lituriit.s)

1.8 3.3 7
0.9 0.8 14
0.7 0.7 4

1.1 0.9 25
0.3 0.0 1
0.3 0.1 2

0.4 0.1

0.0

4.1 .5.6 6 6.2 7.9 5
L7 1.7 2 _ _ _

1.4 0.8 33 0.8 0.6 22 0.4 0.2 6
— — — _ _ _ 0.7 0.0 2

0.7 0.0

— — — 1.2 0.

0.3

21

0.9 0.7

21

0.6

0.3

3

0.5

0.2

1

0.0

0.4

1

0.3

0.4

1

0.4 0.1

1.2 1.1 22 O.t 0.2
0.4 0.2 1

36

0.3 0.4 2 0.3 0.0 2
0.3 0.0 1 0.3 0.0 2

0.7 0.3 12

0.8 0.7 14 ___ ___ ___

1.1 0.8 24 1.7 0.9 10 1.6 1.1 4 0.7 0.4 10

0.3 0.0 1 ___ ___ ___

_ _ _ (),;5 0.1 ,3 0.5 0.2 4 _ _ _

0.3 0.0 1 ___ ___ ___

0,3 0.0 1 ____ ___ ___

— — — _ _ _ 0.6 0.4 2 _ _ —

— — — 0.3 0.0 1 0.6 0..) 5 _ _ _
___ ___ ___ (),:3 0.0 2

0.7 0.5 18 LO 0.7 29 1.3 0.7 30 1.3 0.9 34

_ _ _ _ _ _ ().,3 0.0 6

1998] Bird Usi- or Hii-aiuan Vkcktation' 335

T.\BL1C 2. Coiitiiiiiid.

Specie's

(Scinitilic iiaiiR''')

IlKlfpflldlTlCC

Lower IViRkcf'' L pjicr 'IViieki'i''' Little Tnickcc' (."ii'ek'^

—

—

—

. 1 0.6

17

1.1

0.8

1.2

0.9

23

1.7 1.5

5

2.1

1.4

0.5

0.3

13

_ _

_

_

1

0.3

0.4

4

21

1.3

0.9

26

11

o.s

0.6

22

Warbling \ire(/'* 0.4 0.3 6 1.3 O.S 23 1.0 0.6 23 1.9 1.0 36

iVirco <iiliu.s}
( )ranue-cr()\viH'cl \\'arliler 0.3 0.0 1 — — — — — — — — —

iVenniiora ccUita)
Na.sliville Warbler _ _ _ o.s 0.5 15 0.7 0.0

{W'rmh'tmi ritfic(ipilUi)
VelKm Warbler*' '* 0.5 0.4 10 0.9 0.7 21 1.7 1.2

' Di'udroica fU'tcclna)
Vi'llow-riiinped Warbler 0.7 0.4 10 0.7 0.1 11 0.7 0.1

[Demlroica coroimta )

MacGillivray's Warliler 0.4 0.1 2 0.6 0.2 6 0.4 0.2 3 1.4 0.8 6

{Oporoniis toliniei}
Common Yellow tliroat^^" 0.4 0.1 2 0.3 0.0 1 _ _ _ _ _ _

( Ci'otli I ill lis tri( 7i as )
Wilsons Warbler 0.5 0.2 15 O.S 0.6 11 0.7 0.7 9 0.7 0.6 20

iW'il.sonia pu.silla)
Yellow-breasted Chatt:"^" 0.5 0.3 1 ___ ___ ___

ilcteria viren.s)
Inknown warbler 0.4 0.1 3 _ _ _ _ _ _ _ _ _

Western Tanager<:» 0.4 0.3 3 0.4 0.1 4 _ _ _ _ _ _

( Pirannd ludovicianu )
Black-headed Grosbeak 0.5 0.2 6 0.4 0.1 7 0.8 0.8 2 _ _ _

( Pheuvticus inclanciccplialiis )
Blue Grosbeak 0.3 0.0 1 ___ ___ ___

(Guiraca caentlea)
UxzuM Bnntinu 0.5 0.2 7 — — — ___ __ —

(Passchna ainocna)
Green-tailed Towhee _ _ _ 0.7 0.5 14 0.7 0.5 8 _ _ _

{Pipilo chloninus)

Spotted Tow hee<^B 0.7 0.3 1 0.5 0.2 5 _ _ _ _ _ _

(Pipilo iit(iculatus)
Chipping Sparrow-f^B 0.3 0.1 2 0.3 0.5 3 0.8 0.5 6 0.4 0.2 8

(Spizclld passerina)
Brewer s Sparrow — — — — — — 0.7 0.4 4 — — —

iSpizclla Jireiceri)
Vesper Sarrow — — — — — — 0.6 0.3 4 — — —

( Poocccti'.s '^rainineiis)
Black-throated Sparrow 0.3 0.0 1 ___ ___ ___

{Ainph i-spiza Jjiliiwata)

Sa\annah Sparrow' " 0.5 0.2 1 — — — — — — — — —

iPa.'iscrculii.s .sundwichen.si.s)
Fo.x Sparrow _ _ _ o.5 0.2 8 0.3 0.0 2 _ _ _

{Passerella iliaca)
Song SpaiTow-t^B 0.5 0.3 9 2.1 1.0 .33 1.9 1.6 21 1.1 0.8 22

(Melospiza melodia)
Lincoln's Sparrow _ _ _ 0.6 0.4 2 0.6 0.3 3 _ _ _

(Melospiza lincolnii)
White-crowned Sparrow 0.3 0.0 1 _ _ _ o.9 0.7 6 0.3 0.0 6

(Zonotrich ia leucophnjs )

Dark-eyed junco _ _ _ i.] ().6 17 ].] 0.8 19 1.1 0.7 28

{ Jiiuco hi/enudi.s)
Red-winged Blackbird

(Agelaiiis phocn icens)
Western Meadowlark'-B

(Sturnclla neglecta)

336

Great Basin NATUii\LisT

[\ blumc 58

Tahlk 2. Continued.

Species

(Scientific name^)

Lower rriickee''

L pjici' iVucket''

Little Tnukcc'

Independence
Creeks

Yellou -headed Bkiekl)ird

{Xaiitlioccphalii.s
xanthoccphdht-'i)
Brewer's Blaekl)ird

(Etipha^ii.s ct/aiioci'pliahis)
Brown-lieaded C^owljird''"^

(Molotlinis (Iter)
Unknown hkickliird

Northern Oriole

{Icterus iiulhitla)
Puiple Finch

(Carpodaciis j)uri)iirctts)
Cassins Finch

{Carpodaciis ca.ssinii )
House Finch

(Carpodaciis incxicaiuis)
Pine Siskin

(Cardiielis piiiiis)

Lesser Goldfinch

(Cardiielis psaltria)
House Sparrovv^-'^

(Passer doinesticiis)

1.1 1.6

I.I O.y 14 1.4 1.3 13 I.O 0.8 10 _ _ _

1.5 0.9 32 0.9 0.5 28 0.6 0.4 16 0.5 0.2 22

0.7 0.6 12 ___ ___ ___

1.0 0.5 28 0.3 0.0 1 _ _ _ _ _ _

— — — _ _ _ 0.7 0.7 3 _ _ _

— — — 0.7 0.0 I 0.9 0.5 4 LI 0.7 12

— — — 0.3 0.0 I 0.9 0.2 2 0.8 0.4 6

0.3 0.0 I ___ ___ ___

0.8 0.4 5 ___ ___ ___

■'.Number of hiiils/pdint/coiinl.

''Numl)er of dcteclion.s of tliis six'cie.s/total # c cmiit.s on tins transect.

■-EX = e.xotic or opportunistic species, possibly having a negative impact on native species; NH = species with sensitive nesting habitat, unpaitiil b> alterations

in riparian vegetation: CB = species adversely affected by e.\otic or opportunistic species; ? = species declining tor unknown reason.

''l 19 points, 357 total counts (points X 3)

•^68 points, 204 total counts (points X 3)

'4.5 points, 135 total counts (points x 3)

S18 points, 54 total counts (points x 3)

^AOU 1983, 1995

'Not present

been invalid. In a vegetation type where bird
ealls do not earry well (e.g., dense trees), the
average distanee of deteetion will be smaller
than in vegetation types where bird ealls can\
long distanees (e.g., open grassland). For H ol
10 species examined, average detection distance
did not vary between vegetation t> pes (P >
0.1); the remaining 2 species had 0.05 < P <
0.1. For these 2 species, average detection dis-
tance was shorter in riparian scnib than in otlur
vegetation types. Some of onr data, thercroic,
are slightK', but not nsiially signih'canlly, biased
toward fewer detections in the riparian scrub
vegetation type; however, tlic miinbci ordctct-
tions in this vegetation type lor these species
exceeds detections in any other vegefatioii
type. Also, our survey points often sampled
multiple vegetation types; therelore, the dis-
tance from the point centc-r to a given xcgeta-
tion type \aried. [Riparian \ cgetation Iciulcd

to be most consistently nearer the point cen-
ter, thus explaining some of the bias.

We also conducted chi-s(jnare anaKses to
determine if there is a difference between
general bird use of vegetation t\ pes and a\ ail-
ability of these vegetation t\pes to the birds.
Ik'canse our sur\ey focused on nonagiiciil-
tural vegetative relationships, for this aiuiKsis
wc excluded indi\'idual birds detected in a'j;ii-
cultural areas and areas that were not (juanli-
lic-d on vegetation maps (36% of all detections).

rhronghoiit this paper \\t' discuss general
ti<'iids lor all bird species, loensing on 21 a\iaii
speeies ol special interest (Tables 2, 4). These
s|)eeies inilude those thought to be decreasing
ill abmidaiK-e due to eompetition Ironi ojipoi-
liiiiistic and exotic siieties or thought to be
iiii|Kicted by alterations ol riparian vegetation.
()llier species ol interest nia\ be ineii'asing
oppoitmiistic and exotic s|)ciies (e.g.. Brown-

1998]

BiKH I'si: ()|- Kii'Miiw Vkcktatiox

337

licadi'd { low l)ir(l. [''.iiropcan Sfarliiiu, I louse
Sparrow ) that ina\ acK crsel) impact riparian
birds. Idi-ntilication ol tlu'se species of special
iiilcTcst was desipiatcd 1)\ the USF\V\S l)ased
oil re\ iew ol prexious works (Ridiiwax' 1(S77,
Kleheiiow and Oakleaf 1984) and coiiiniunica-
tion with regional biologists (USFWS, Caliloi-
nia Parks neiiartnient).

Hi:sriTs

Species Richness and
Abundance ol Birds

( )\ IH \i.i,. — We detected 1 Hi specie's across
the entire stud\' area. The most abundant
species o\ erall was Cliff Swallow, followed b\
American White Pelican, Song Sparrow, Turkey
Wiltiue, Northern Rough-wdnged Swallow, and
I louse Wren (Table 2). Mean ± s of ])ird species
richness per point was 16 ± 4 among transects
on the lower Truckee, 14 ± 4 on the upper
Truckee, 13 ± 2 on the Little Truckee, and 13
± 4 on the single Independence Creek tran-
sect. Total bird abundance on each transect
ranged between 8.7 and 14.8 birds/point/count,
with a mean of 11.2 ± 1.8 birds/point/count.

Lower Truckee River. — The most fre-
quentK' detected bird species along the lower
Truckee was the Brown-headed Cowbird, fol-
lowed by Noilhem Oriole, Black-billed Magpie,
I louse Wren, Red-winged Blackbird, Emopean
Starling, Northern Rough-winged Swallow, and
Mallard (Table 2). Eighteen species of special
interest were detected along the lower Truc-
kee, 4 at > 10% of the counts and the remain-
ing 14 at <97c of the counts (Table 2).

Upper Truckee River. — The most fre-
quently detected species along the upper
Truckee was the Song Sparrow, followed b\'
Steller s Ja\, American Robin, Brown-headed
Cowbird, Warbling Vireo, Western Wood-
Pewee, Mountain Chickadee, Yellow Warbler,
and Spotted Sandpiper Twelve species of spe-
cial interest were detected along the upper
Truckee, 4 at >20% of the counts and the
remaining 8 at <6% of the counts (Table 2).

Little Truckee River. — Along the Little
Truckee the most frequently observed bird
species was the Western Wood-Pewee, fol-
lowed by American Robin, Warbling Vireo,
Steller's Jay, Mountain Chickadee, Song Spar-
row, Spotted Sandpiper, and Yellow Warbler.
Seven species of special interest were detected

along the littli' IVuekee: 4 were detected at
> l()7f of the counts and 3 at <6% (Table 2).

Independence C:heek. — The most fre-
(|uentl\ detected bird species on Indepen-
dence ("reek was the Mountain C'hickadee,
followed by Warbling Vireo, Western Wood-
Pewce, American liobin. Dusky Flycatcher,
Dark-eyed junco, unidentified Empkhmax fl\-
catchers. Yellow Warbler, Brown-headed Cow-
bird, Song Sparrow, Yellow-rumped Warbler,
and Wilsons Warbler. Se\en species of special
interest were detected along Independence
Creek: 4 were detected at >2()% of the counts
and 3 at <8% (Table 2).

Over all sections of the river, <2 individuals
of each of the most fretjuently detected
species were obserx ed during any single point
count (Table 2).

Distribution of Birds
by Vegetation Type

Richness and percent occurrence of

BIRDS .A.MONG VEGETATION TYPES. — We (lid UOt

sample each vegetation type equally through-
out the Truckee River drainage; therefore, the
following 3 results sections should be consid-
ered as baseline data to be compared with
future avian sampling.

The highest bird species richness occurred
in the riparian scrub vegetation type, with 17
species detected only in riparian scrub. Sage-
brush steppe, riparian scrub with whitetop,
mature Fremont cottonwood with and without
whitetop, pole-sapling Fremont cottonwood
with and without whitetop, whitetop alone,
and Sierra mi.xed conifer also had high species
richness (>40; Table 3). Of 116 bird species
observed during our study, only the Pine
Siskin, White-breasted Nuthatch, White-faced
Ibis, Blue-Cra> Cnatcatcher, Brown Creeper,
Black-throated Sparrow, Cedar Waxwing, and
Hairy Woodpecker were never detected in
native riparian \egetation.

Species richness was 30% less in riparian
scrub that contained whitetop. However, bird
richness in Fremont cottonwood was the same
with and without whitetop (Table 3).

Riparian scrub \egetation had the highest
percentage of detections of all species over all
points in our study. Sagebrush steppe was the
only other xegetation type with > 10% of all
birds detected. No single successional stage of
cottonwood had >8% of all detections; how-
ever, 21.2% of all birds observed were across

338

Great Basin Natl halist

[\r)lume 58

Tabi.F 3. Species richness (niimher) and perccnta.^e oi a!
\icinity, California and Ne\ada, spring 1993.-'

l)irds iletected (%) by vegetation t\pe. Tincki-e liixcr and

Vegetation tyjie''

.Number

Pole-sapling l-VeTnont cottonwood-willow

Matme Fremont cottonwood-willow

Seedling Fremont cottonwood-willow with wliitetop

Pole-sapling Fremont cottonwood-w illow \\ itli wliitetop

Matme Fremont cottonwood-u illow with w hitetop

Riparian scrub

Riparian scrul) with wliitetop

Wliitetop

Sage steppe

Marsh

Gra\el bar

Seedling black cottonwood

Pole-sapling black cottonwood

Mature black cottonwood

Jeflre\' pine

Lodgepole pine

Sierra mixed conifer

Agriculture

49
53

9
48
57
93
62
49
77
27
17

5
18
28
39
40
42
34

3.3
6.6
0.1
3.7
7.5

28.7
9.6
4.3

14.0
1.6
0.5
0.1
O.S
1.5
4.1
5.8
5.7
2.1

^Based on 11,812 observiitioiis

"See Appendix for hill description ol \i-i;ctati(in t\pes.

all .stages of Fremont cottonwood. Pure white-
top stands supplied 4.3% of all detections
(Table 3).

The percentage of individual birds detected
was low in all conifer vegetation types (<6%).
Overall, the 3 conifer vegetation types — Jef-
irey pine {Pinusjejfreyi), lodgepole pine {Piiiiis
contorta van murrayana), and nii.xed conifer —
contained 15.6% of all birds detected. Black
cottonwood, which occurs within the conifer
zone, contained onlv 2.4% of bird occurrences
(Table 3).

BlRI3 SPECIES DETECTIONS ACROSS VECEIA-

TION TYPES. — Thirteen species were detected
in >1() vegetation types, whereas 40 species
were detected in <3 different types. Brown-
headed Cowbirds (Table 4) and American
Robins were detected in all vegetation t\pcs,
and both were most commonly detccled in
riparian scrub vegetation.

Frequency of bird species of si'eciai,

INTEREST AMONG VEGETATION TYPES. — We con-
sidered a bird species to be rare if it was
detected with a lre(iuency of <2.5% (during
<2() of the 750 total point counts).

E.XOIIC OR OPPORTUNISTIC SI'IXMT.S. — lirowil-
headed (Jowbirds were common and were
detected in all xcgetation t\pcs, though less
lre(iuentl\ at higher elexations (Table 4).
iMn-opean Starlings were ficcinciilly dclcclcd
at lower elevations where thcic were Irccs,
and also in sagehiiish slc|)|)c. SiinihiiK, llic
introdnccd I louse Sparrow was iiiosi Irc-

quently detected in Fremont cottonwood and
riparian scrub at low ele\ations. Both starlings
and House Sparrows were detected primarily
near buildings and agricultural fields.

Species possibly affected by e.xotic or

OPPORTUNISTIC species, UNKNOWN REASONS, OR
ALTERATION IN RIPARIAN VE(;ET\TI0N. — C:alifor-

nia Gulls, Common Yellowthroats, Spotted
Towhees, Tree Swallows, Willow Flycatchers,
Marsh Wrens, Chipi:)ing Sparrows, Sa\annah
Sparrows, and Yellow -breasted C-hats were
rare but most often detected in riparian scrub
(Table 4). Tree Swallows were also obserxed
nesting in mature black cottonwood. Oli\e-
sided FKcatchers, thought to be declining
throughout the West (Bobbins et al. 1986,
DeSante and George 1994), were most often
obserxed in Sierra mi.xed conifer and riparian
scrub. Western Meadowlarks were fairly Ire-
(luent across most \egetation txpcs, and \ io-
let-Green Swallows were oiiK raicK clett'ctcd;
both species were deteeti'd only at lower ele-
N'ations. Song Sjiarrows were common and
Western Tanagers were rareb deti'cted: both
wcic seen acioss most vegetation I\ih's. War-
bling Xireos were li('<|iieiit in riparian scrul),
l()dge|M)le pine, and black lottonwood. Yellow
W'arbk-rs wtMi- detected across all ripaiian
t\pes, most IrecinentK' in riparian scrub.

Si'i;( ii:s I'ossiHL'i i\ii'\( ii d in \i ii.kviion
l\ lill'Mil \\ \ ici: I VH( )\.- liaiik Swallows wcic
most lr('(|U(nll\ (Ictcctcd in I'Veniont cotton-
wood and sailehnisli stciiiie (Table 1). Ilair\

1998]

Biiu:) VsE OF Hii'\m w Vegetation

339

TaBLIl 4. Peifi'Mt cU'ti'ctioiis olspi't-ii's of six'tial iiitcifsl aiiioiit; Ni'i^rlatioii txpcs' aloiii; tlif IViickfi- liivcT and xitiiiitx.
California and \i'\ ada.

Species

cw

ew -Hw'

rs

■s + w

w

ss

m

u

be

jp

Ip

snic

a

Iv\ntic/()pportinii.stic

lunopean Stailini:

U)

31

22

13

4

12

<1

<1

0

0

0

0

0

Bioun-lu'adi'd Cow bird

13

12

2fi

13

8

17

•T

1

2

1

1

4

<1

House Sparrow

;5ij

10

49

3

0

0

0

I)

0

0

0

0

0

(Competition witli exolies oi

iniidentiiied

ii'asons

()li\e-sided Fl\ catcher

0

0

31

8

0

0

0

0

0

8

8

46

0

Willow FKcatcIier

0

0

100

0

0

0

0

0

0

0

0

0

0

Tree Swallow

0

0

42

2

0

0

0

1

16

2

0

0

0

V'iolet-Creen Swallow'

0

33

0

0

0

67

0

0

0

0

0

0

0

Marsh W'ren'^

0

0

0

(i7

(1

33

0

0

0

0

0

0

0

W'arhlinu N'ireo

1

14

32

3

1

1

0

0

17

2

18

12

0

^ellow Warbler

s

17

43

10

2

4

1

0

9

0

3

4

1

( lomnion Yellow throat

9

IS

0

36

9

18

0

0

0

0

0

9

0

Yellow -breasted Chat'

0

25

13

50

1:5

0

0

0

0

0

0

0

0

Western Tanager

15

20

10

15

0

0

5

5

5

5

0

20

0

Spotted Tow hee

0

0

47

24

0

6

0

0

12

6

0

6

0

(.'hip|)in,u Sparrow

0

0

40

0

20

20

0

0

0

0

0

20

0

Sa\annah Sparrow

0

0

H7

0

0

33

0

0

0

0

0

0

0

Song Sparrow

5

2

64

1

2

"■

<1

0

5

2

2

12

0

Western Meadowlark

28

2fi

13

19

2

12

0

0

0

0

0

0

0

Impacted b\- loss of haliitat

or \egetation

alteration

(California Cnll

0

0

100

0

0

0

0

0

0

0

0

0

0

Hain Wbodjiecker

0

0

0

0

0

0

0

0

0

0

0

100

0

Bank Swallow

4S

0

24

8

8

32

0

0

0

0

0

0

0

■'N'egetation hpes and codes found in Appt'iidix.

"+w = vegetation type mixed with wliitetop.

'^Also affected h> loss of habitat or alttiatioii of vegetation.

\\b()clpeckers were detected only in Sierra
mixed conifer. Both species were rare.

Use nersls axailability of vegetation
n PES. — 0\erall, birds did not use vegetation
t\ pes in proportion to their availabiHtv' (/^ =
7254, df = 8, P < O.OOl). The discrepanc\- be-
tween use and a\ailabilit\' was highest in ripar-
ian scrub and Fremont cottonwood. Although
totaling only 10% cover (Table 1), riparian
scrub/mixed willow was used by birds almost
40% of the time during our obser\ations. Bird
use of monotv'pic whitetop was significantly
less than expected given its percent cover. The
number of bird species using these vegetation
t\ pes supports oiu" findings of bird preference:
Fremont cottonwood, 70 species; riparian scrub/
mixed willow, 80 species; and whitetop. 44
species.

Discussion

0\erall Distribution and
Abundance of Birds

The lower Truckee Ri\ er harbored the great-
est richness of a\ifauna of an\ stream section
we monitored. This was due primariK to the

section's extensive riparian scrub and Fremont
cottonwood stands; these \egetation types
decreased in area with increasing elevation
(USFWS 1993) on the upper stretches of the
river. Higher-elevation black cottonwood com-
nmnities did not replace lower riparian scrub-
cottonwood conmnmities in terms of bird
species richness. Elevational temperature gra-
dients and arthropod abundances were not ex-
amined in this stud) but ina\ have contributed
to knels of species abundance we observed.
Black and Fremont cottonwood each occupied
similar absolute areas (Table 1); hence, differ-
ences in bird richness were unlikcK due to an
area effect.

Transects at higher elevations were com-
posed of coniferous vegetation with a narrow
strip of streamside riparian xegetation; a conifer
oxerstoiy was often present at streamside. In
contrast, transects at lower elexations were pre-
dominantly riparian, with a cottonwood over-
stor\' and scrub understor\'. Thus, by virtue of
abundance of vegetation types alone, lower-
elexation areas should be dominated b\ ripar-
ian-associated bird species, while upper-ele\'a-
tion areas should have fewer riparian-associated

340

GuEA'i Basin Xailiulist

[N'olume 58

bird species. Knopf (1985) and Finch (1991b)
also reported different bird conniiunities asso-
ciated with different elevations.

Species-specific Considerations

The Brown-headed Cowbird was widely
distributed but reached its highest numbers at
lower elevations where agriculture was promi-
nent (Table 1). These birds t\picall\' forage in
agricultural areas while sometimes tl\ ing long
distances to find forested nesting habitat. The
Brown-headed Cowbird was the most fi-e-
(juentK encountered bird along the lower
Truckee and was also found in the greatest
number of vegetation types, 'i'ellow Warbler,
Warbling Vireo, Common Yellowthroat, Yel-
low-breasted Chat, and Song Sparrow were
also detected during our stud\' and are known
to be adxerseK' impacted b\' cowbird nest par-
asitism (Friedmann et al. 1977).

European Starlings, common along the
lower Truckee, were especially numerous near
agricultural fields and buildings; their num-
bers decreased rapidly with increasing eleva-
tion. Therefore, their potential impact on cav-
ity-nesting species may be of primary concern
only at lower elevations (Stoner 1939, Jackson
and Tate 1974). House Sparrows were rare
and were detected primarily around buildings.

Willow Flycatchers, which are declining in
the West (DeSante and George 1994, Roth-
stein and Robinson 1994), were detected at
only 1 point on the upper Truckee River and
nowhere else. Dates of the sightings (18 and
24 June) suggest the probabilitv of breeding
activity (Bent 1942, McCain- ancl Hovel 1991),
but we were unable to confinii this.

Avifauna of Little Truckee \{\\vv and Inde-
pendence Creek were dominated by species
txpical of coniferous forests. However, War-
bling Vireos, Song Sparrows, and Yellow War-
blers, all riparian-associated species of concern,
were also common in both areas throughout
the study. In addition, the Wilsons Warbler,
another riparian-associated species, was coui-
nioniy observed on independence (]reek and,
to a lesser extent, on the upper Truckee and
Little Truckee. Even in these coniler-donii-
nated areas, small patches of riparian xcgeta-
tion apparently are enough to siipi)()rl these
riparian-associated bird species.

Species liiehness in Negelalioii

I'Vemont eottouwood and riparian scrub
willow were used l)\ a wide \ariet\ ol birds

and with a much greater frequenc\- than their
availability. Therefore, a drastic reduction in
native riparian forest abundance may have more
effect on birds than a reduction in an\' other
plant species along the Truckee Ri\ er. Habitat
specialists (40 species found in <3 different
habitat types) were observed most frequently
in riparian scrub. Even the habitat generalists
in our stucK (Brown-headed Cowbird and
American Robin — the bird species found in
the greatest number of different vegetation
types) were most fre(|uently obsened in ripar-
ian scrub. Therefore, both dominant riparian
vegetation plants — cottonwood and willow (the
dominant plant species in riparian scrub) —
should be considered in developing manage-
ment plans for protecting the habitat of Truc-
kee River bird species.

Because 98 of 116 bird species were de-
tected in native riparian vegetation, 22 exclu-
sively, the majorit\ of bird species would be
impacted in some way by altering nati\ e ripar-
ian plant communities. Although sagebrush
steppe also had a high species richness, this is
probably due to its proximitx' to riparian \'ege-
tation, creating an ecotone that attracts more
species than the sagebrush-steppe vegetation
t\'pe alone (Gates and Gysel 1978).

Impacts of Exotic Vegetation

The major exotic plant of interest in our
study was whitetop, or peppergrass. Whitetop
was used b\ bird species for foraging (S. L\nu
personal observation), but nesting in this plant
species was not documented. Whitetop was
negati\'el\' associated with bird species rich-
ness in riparian scrub; however, bird richness
in iMcmont cottonwood did not differ with tlu'
presence of whitetop. Further research in this
area is neccssaiy to determine wlulhei there
is a cause-effect relationshij') between whiti"-
top and bird species richness.

In sunnnar)', a \aried flow regime, oxergraz-
iug, chaimeli/ation, and other human acti\ ities
ha\i' altered riparian vegetation along the
li nekee Kixcr and its tributaries (Klebenow
and Oakleal 1984). Destrnelion and icnioxal ol
native cottonwoods and w illow s lioiii the ripar-
ian corridor has likeK resulted in a decreasi'
ill numbers ol rijiarian obligate bird species, a
historical issue which will be presented in a
liitnre manuscript. Also, a\ ian exotics and op-
lioitiiiiistie si)i'eies, such as the Brown-headed
('owbird, eoiild |i()teiitiall\ reduce sensitixe

1998]

BiHD UsK OF Hiiniu \\ Vegetation

341

spc'C'it's rithness and ahmulaiict'. TIh' ettects ol
fowhird parasitism and rxotic species on seii-
sitixf bird species in tlie Truckee HixtT area
warrant luither investigation. Also warrantinu
further in\ estimation is the effect that the
exotic plant species whitetop nia\' ha\e on bird
distril)ution. L nfbrtunatcK', whitetop is an
especialK hard) species that is difficult to
eradicate (Rosenfels and Headley 1944). Man-
agement plans ma\ ha\e to consider it as a
permanent aspect of the riparian community
and concentrate on keeping existing patches
of the plant from spreading into nati\e ripar-
ian habitats.

Managers who are interested in halting
declines in bird populations and stinudating
growth in these populations should consider
protecting existing native Fremont cottonw'oods
and riparian scrub \egetation, as well as per-
haps initiating restoration of these \egetation
t)pes in degraded areas. Data that we collected
w ill be valuable as a baseline from which to
compare future bird sur\'e\'S along these rivers
as land uses change or continue in degradation
of nati\e riparian forest. Future researchers
will be able to use our data to discover and
confirm trends among bird species and their
vegetation reciuirements along the Truckee
River and \ icinit).

Acknowledgments

We thank the U.S. Fish and Wildlife Ser\ice,
especialK Da\ id L. Harlow of the Reno Field
OflRce, for consulting on logistical airangements
and financialK" supporting this project. We
also thank Sagehen Creek Field Station, Uni-
\ersit\' of (>ali{ornia, for providing housing;
tlie landow ners along the Truckee, Little Truc-
kee, and Independence Creek for allowing
access to their property; and several anonv-
mous reviewers, as well as (and especially)
Steve Knick. lor criticjues of this manuscript.

Literature Cited

American Ornithologists' Union (AOU). 198.3. Check-
li.st of North American Birds. 6th edition. Allen Press,
Inc., Lawrence, K..S. 877 pp.

. 199.5. Fortieth supplement to the American Orni-
thologists" Union check-hst of North American Birds.
Auk 112:819-8.30.

Bent, A.C. 1942. Life histories of North American flycatch-
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Museum Bulletin 179. Smithsonian Institution, U.S.
Go\ernment Printing Office. Washington. DC. .^.^.d
pp.

liloNDll. J.. (.'. Fr.Hin. AM) B. Fhociiot. 1981. Point counts
with unlimited distance. Pages 414-420 iu C^.J.
Balph and J.M. Scott, editors, Estimating numbers
ol terrestrial birds. Studies in .'\\ian Biology fi.

HorroHir, B.L. 1974. Cottonwood habitat for birds in
(Colorado. American Birds 28:97.5-979.

DkSanti:, D.F, andT.L. Gkorci;. 1994. Population trends
in the landbirds of western North Airierica. Sfudii's
in Avian Biologv 15:17.3-190.

Fi\c:h, D.Vl. 1991a. Population ecology lial)itat retjuire-
ments, and conser\ation of .Neotropical migratoiy
birds. General Technical Report R.Vl-20.5. U.S.
Department of Agriculture, Forest Service, Rocky
Mountain Forest and Range E.\|)eriment Station,
Fort Collins. CO. 26 pp.

. 1991b. Positive associations among riparian bird

spi'cies correspond to eIe\ational changes in plant
commiimfies. (Canadian journal ol Zoologv 69:
9.51-963.

Friedmann, H., L.K Kike and S.I. Rotiistein. 1977. A
further contribution to knowledge of the host rela-
tions of the parasitic cowbirds. Smithsonian Contri-
butions to Zoolog)' 2.3.5. Smithsonian Institution
Press, Washington DC. 75 pp.

Gates, J.E., .\ND L.W. Gysel. 1978. Avian nest dispersion
and fledging success in field-forest ecotones. Ecol-
og\' .59:871-83.

Jackson, J.A., and J. T.\te, Jk. 1974. An anahsis of nest
box use by Purple Martins, House Sparrows, and
starlings in eastern North .Vmerica. Wilson Bulletin
86:43.5-449.

Ki.ebenow, D.A., AND R.J. Oakleae 1984. Historical a\i-
faunal changes in the riparian zone of the Truckee
River, Nevada. Pages 20.3-210 ;';; R.E. Wanier and
K.N. Hendri.K, editors. California riparian systems.
UniversitN' of California Press, Berkele\'.

Knope, el. 1985. Significance of riparian vegetation to
breeding birds across an altitudinal cline. Pages
10.5-111 in R.R. Johnson, CD. Ziebell. D.R. Patten,
RE Ffolliot, and R.H. Hamre. technical coorthnators.
Riparian ecos\stems and their management: recon-
ciling conflicting uses. General Technical Report RM-
120. U.S. Department of .\griculture. Forest Ser\ice.

Martin, T.E., .\nd D.M. Finch. 1995. Ecology and man-
agement of Neotropical migraton* birds: a s\nthesis
and review of critical issues. O.xford l'ni\ersity Press,
New York. 489 pp.

Mc:Cabe, R.A., and S. Hovel. 1991. The little green bird:
ecolog)' of the Willow Flycatcher. Rust> Rock Press,
Madison, \VT.

Ml RRU, N.L., AND D.F S TAi EFER. 1995. Nongaiue bird
use of habitat in central .Appalachian riparian forest.
Journal of Wildlife Management 59:78-88.

R\LPii, C.J., G.R. Gelpel, P Pile. TE. .Martin, and D.F
DeSante. 1993. Handbook of field methods for moni-
toring landbirds. General Technical Report PSW-
GTR-144. U.S. Department of Agriculture, Forest
Service, Pacific Southwest Research Station. 41 pp.

Raphael, M.G. 1987. Estimating relative abundance of
forest birds: simple \ersus adjusted counts. Wilson
Bulletin 99:12.5-131.

Reynolds, R.T. J.M Scotl and R.A. .Nisshai nl 1980. A
variable circular-plot method for estimating bird
mmibers. Condor 82:309-313.

RiDc;\\AV, R. 1877. Omitholog\. Pages .303-669 in C. King,
Omitholog> and paleontolog\-. U.S. Geological E.xplo-
rations 40th Parallel 4.

342

Great Basin Naturalist

[Volume 58

Bobbins, C.S.. D. Bystrak, and RH. Gkissler. 1986. The
breeding bird siin'e\-; its first fifteen years, 196.5-1979.
L nited States Fisli and Wildlife Ser\ ici'. \Vashinti;fon
DC.

BosENFELS, B.S., AND KB. IIeadlev. 1944. Whitetop eradi-
cation. Bulletin 170. University of Ne\ada .\griciil-
tural Department. 18 pp.

BoTllSTEiN, S.I., AND S.K. BoBlN.soN. 1994. ConstiA ation
and coe\olutionan implications of brood parasitism
b\' cowbirds. Trends in Ecologx' and Evolution 9:
162-164.

Sliwa, a., AND T.W. Sherry. 1992. Sur\e\ing wintering
warbler populations in Jamaica; point counts with
and without broadcast vocalization. Condor 94;
924-936.

Sprunt, a., IV. 1975. Habitat management implications of
migration. Pages 81-86 in Proceedings of the sympo-
sium on management of forest and range habitats for
nongame birds. General Technical Report WO-1.
U.S. Department of Agriculture, Forest Service, Tuc-
son, AZ.

Stevens, L.E., B.T. Brown, J.M. Si.vipson, and B.B.
Johnson. 1977. The importance of riparian habitat
to migrating birds. Pages 156-164 in R.R. Johnson
and D.A. Jones, technical coordinators. Importance,
preservation, and management of riparian habitat.
General Technical Report RiVI-43. U.S. Department
of Agriculture, Forest Sei^vice, Tucson, AZ.

Stoner, D. 1939. Parasitism of the English Sparrow on
Northern Cliff Swallow. Wilson Bulletin 51;221-222.

Stkonc, T.R., AND C.E. Boc;k. 1990. Bird species distribu-
tion patterns in riparian habitats in southeastern .Ari-
zona. Condor 92;866-885.

Sz.\RO, B.C., .WD M.D. Jaki.E. 1985. .Avian u.se of a desert
riparian island and its adjaccTit scrui) habitat, (aju-
dor 87:511-519.

U.S. Fish and Wildlife Sfrmce (USFWS). 1993. Truc-
kee River riparian vegetation and flu\ial geomor-
phology study. Ai)pendi.\ C. Truckec Bi\er riparian
corridor co\er and land use t\pes. U.S. Department
of the Interior, U.S. Fish and W'ildliie Service, Sacra-
mento, CA.

Verner, J. 1985. An assessment of counting technicjues.
Current Ornitholog) 2;247-.302.

Wauer, B.H. 1977. Significance of Bio (irande riparian
systems upon the avifauna. Pages 165-174 in B.B.
Jolinson and D.A. Jones, technical coordinators,
Importance, preservation, and management of riparian
habitat. General Technical Beport BM-43. U.S. Depart-
ment of Agriculture, Forest Sen ice, Tucson, AZ.

Received 20 Xov ember 1995
Accepted 13 Xoiendx'r 1997

Appendlx. Major vegetation types along the Triiekee River, California and \e\ada (USFWS 1993).

Code

Vegetation type and characteristics

Sierra mixed conifer forest: An open, parklike forest of coniteroiis evergreens with crowns
often touching. Several predominant species; Abies. Psciidotsti^a, and Conms are most
common on moist sites; Pi)iiis spp. and Cc(i)iotlius spp. on dn sites. The underston' typi-
cally is sparse, consisting of scattered chaparral shrubs and Noung trees. Kle\alioii:
1500-2100 nL

JP

Jeffrey pine: A tall, open forest predominated hy Jeffrey pine, with sparse understor\- ol
montane chaparral or sagebrush spp. Elevation: 2100-2750 m.

Ip

Lo(h^^ef)()le })iiie: 'lypicaIN a dense forest of slender trees up to K) in tall, oltcii in purr
stands. Klexation: 2100-2750 m.

Bldck cottoiiicood: A lairK dense, mi.xed rijiarian forest predominated In Mack cottonwood
with Jeffre\ pine and/or lodgepole pine. The shrub and herb la>ers are well de\ eloped. Ele-
vation: usualK > ISOO m.

i'.rcdl Basin ((illoitudod-itillou' forcsl: ( )pen-i'anopied loresl picdoiiuniilcd l)\ iVcniont
cottonwootl auti Salix lacii^dld (piimarily east oi \isla). Elevation: usualK <2100 m. Iliis
tNjK' was further delineated 1)\ the presence oi whitetop ("/w" added to ending ol tvpc
code) and hy successional slagi': e\\2 = shruh seedling (<■') m t;il!l: c\\> = iiolc-sapling;
cw4 = mature.

Cereal Basin rijiarian scrub: Open to diMisc ripaii;iii ihickcis usualK coniposcd ol willow.
Open stands max lia\c' a dense herbaceous iukK istor\. l'",lf\;itioii: ;ill. but espeiialK well
developed along lower 'IVuckee.

1998] Bird Usi: OF Hii'Mii \\ Vkcetation 343

Al'l'IADIX. (loiltillllcil.

Code Wgetation t\pe and charactenstics

ss S(i<ichntsh steppe: A seniidosed steppe predominated 1)\ hig ,sagel)nisli with sexfial

perennial hnnehgrasses between slniihs. Elexation: helow eonifer zone.

Ml Freshuater marsh: Predominated h\' perennial, emergent monocots. Sciri)iis and Tijpha

dominate. Sites lack current, often permanently floock'd freshwater (haelcwater of I)erh\-
Dam. oxbow).

a Aspen: Dense stands of usually mature aspen located within eonifer zone.

g Gicivel Ixirs.

w Whitetop: Low, dense, exotic forb. Dead stalks persistent and woocK. Often is dominant

miderston' for Fremont eottonwood. Ele\ation: <1(S()() m.

ag Agrieiilture, mostly alfalfd.

Great Basin Naturalist 58(4), © 1998, pp, 344-351

USE AND SELECTION OF BROOD-REARING HABITAT BY
SAGE GROUSE IN SOUTH CENTRAL WASHINGTON

Colin M. Svt'imi', Jolin A. Crawford-, and W. Daniel Edge-

Abstbact. — Sage Grouse (Centraccrcus tirophasiaims) hrood-lialjitat use was exaiuined cliuinti 1992 and 1993 at tlie
Yakima Training Center in Yakima and Kittitas counties, Washington. During the 2 yr we followed 38 i)r()ods, of which
12 persisted to 1 August (.v = approxiniateh- 1.5 chicks/brood). Food forh cover was greater at all brood locations than at
random locations. Hens with broods in big sagebrush/liunchgrass habitat (Artonisia iridentutalA^ropyrim spicatum]
selected for greater food forb cover, total forb cover, and lower shrub heights; broods in altered big sagebnish/liimch-
grass habitats selected greater tall grass cover and vertical cover height; broods in grassland showed no preference for
any measured vegetation characteristics. During the early rearing period (post-hatching-6 wk) each year, broods
selected sagebnish/liunchgrass. Broods in 1993 made greater use of grasslands than in 1992 and selected grassland dur-
ing the late brood-rearing period (7-12 wk). Broods selected for sagebrush/ljunchgrass during midday, but 52% of brood
locations in the afternoon were in grassland. Tall grass cover was greater at morning (0500-1000 h) and afternoon
(1501-2000 h) brood locations than at midday (1001-1500 h) and random locations. Midday brood locations had greater
shiaib cover and height than morning and afternoon locations. Selection of habitat components was similar to the results
of other studies, but habitat conditions coupled with a possible lack of alternate brood-rearing co\er types resulted in
low sur\'i\al of chicks.

Key words: broods, Centrocercus mophasianus, Jiahiiai. Saac Grouse. \Vasliiii0oii.

Habitat use by Sage Grouse {Centrocercus
urophasianus) for brood rearing was related to
forb a\ailabilit\' in previous studies (Peterson
1970, Oakleaf 1971, Autenrieth 1981, Drut,
Crawford, and Gregg 1994, Drut, Pyle, and
Crawford 1994). Sage Grouse ehieks recjuire
protein-rieh foods, iueluding inseets and forbs,
ior growth and development from hatching
through appro.ximately 3 mon (Savage 1969,
Dunn and Braun 1986, Bergerud 1988, Drut,
Pyle, and Crawford 1994). Changes in avail-
al)ility of these critical foods may affect Sage
Grouse distribution and habitat selection
(Wallestad 1971, Pyle- 1993). Fintliermore, in
an Oregon study (Drut, Pyle, and Crawford
1994), Sage Grouse productivity was higher
on an area where chicks fed on a diet of 809^
forbs and insects than where chicks ate pri-
marily (65%) sagebrush {Artemisia spp.).

Sage Grous(> broods reportedly nio\e from
nesting habitats to sites where succulent and
abundant lorbs persist (i.e., meadows or upland
sagebrush habitats) as sunnner tcmpci'aturcs
increase and nioisliirc dci rcascs (Nelson
1955, (;ill 1965, Sa\agc 1969. Oakleaf 1971,

Autenrieth 1981). Brood movements to these
habitats are immediate or transitional depend-
ing on annual precipitation, temperatiu'c, and
proximit)' from nesting habitat. Meadows and
upland sagebrush habitats, however, often have
been grazed e.\cessi\eK, causing reduced food
and water availabilit\' (Saxage 1969, Oakleaf
1971). Disturbance in these mesic habitats has
increased soil erosion, facilitated iinasion b\
e.xotic plants, affected \egetati\t' composition,
and lowered water table lexels (Oakleaf 1971,
Hofmanu 1991). Oakleaf (1971) found fewer
Sage Grouse foraging in Nevada meadows as
food supplies diminished because of improper
grazing practices and soil erosion. In Oregon,
Drut, Crawford and Gregg (1994) noted tliat
bloods used hnger home ranges where forb
a\ailal)ilit\ is low than where lorbs are relati\c'l\
abundant. This max liaxe resuiled in reduc-ed
sur\i\al. These studies icxeai the importance
ol lorbs and insects in relation to al)ini(hnn'e,
distribution, habitat selection, and pmdnetiv il\.
\e\('i"theless, the elfeet of massixe hnidseaj)!'
changes on habitat use b\ broods has lareK
been doeuniented. A (nil nndeistanding ol

'Unilc-d Stales Gcolodical Siirxcy— HioloKical Rc-soiircfs OK imom, I pp.-r Mississippi Siiiiuc ( :<iil<i, 2(i.?(l I'.iiil.i U. rd lin.al I ,.i( mss. W i "i IlidV
^Department of rislicries and Wildlife. Oregon State Univirsilj. CioiA.illis. OH 97:331 -,3803.

34-

1998]

Sack Grouse Biuk)!) II \nv\\T Sklkction

345

iactors atlecting habitat use I)\ hioods, t'spc-
cialK where popuhitions are severely depleted
in areas of inassi\e habitat ehanc!;es, remains
incomplete.

We studied Satie Cirouse in Washinuton
where extensi\e habitat loss (approximateK
7{)'( ) and altiTation ha\c induced Sage Grouse
to 2 si'paiate populations totaling an estimated
(i3() birds b\ 1994 iTirhi 1994). Our objectives
were to e.xamine selection ot c()\er types by
Sage Grouse broods and describe structure
and composition of habitat components within
c()\er t\pes (3rd- and 4th-order selection,
respecti\el\'; see Johnson 1980) used by broods.

Study Area

The stud) was conducted on the Yakima
Training Center (YTC), a 1058-km2 area in
Yakima and Kittitas counties, Washington,
which supported approximately 330 Sage
Grouse during this study (Tirhi 1994). Eleva-
tions on the YTC range from 183 to 1249 m.
Hot, diT summers and cool, drx' winters t\'pify
the stud>' area. Growing season (September-
August) precipitation for 1962-1993, obtained
from the U.S. Department of Commerce Cli-
matological Database, a\eraged 20.4 cm; grow-
ing season precipitation in 1991-92 and
1992-93 was 16.7 and 22.5 cm, respectively.
Above normal precipitation accompanied b\'
cooler than axeragc temperatures began dur-
ing winter 1992-93 and continued through
summer 1993. These weather differences likely
accounted for greater shrub cover and height
and more tall grass and forb cover in certain
c()\er t\pes in 1993 (Sveum 1996).

Because the \TC sen es as a militaiy train-
ing ground, frequent off-road-vehicle use has
resulted in approximately 5% of the area being
covered by roads and trails (J.G. Stephan,
Pacific Northwest Laboratory, personal com-
munication). This disturbance has increased
erosion and facilitated establishment of knap-
weed {Centaurea spp.) and cheatgrass brome
{Bromiis tectorum). Cattle and sheep grazing
was initiated on the YTC in 1961; livestock
stocking rates during 1992 and 1993 were 0.13
and 0.15 animal unit months/ha. Fires on the
YTC, common during summer, burned 5.3 and
8.0 km2 in 1992 and 1993, respectively (L.L.
Cadwell, Pacific Northwest Laboratorx, per-
sonal communication).

We icK'utilied 5 coxt-r l\pes axailable foi'
brooding Sage Grouse on the YTC: (1) i)ig
sagebrush (A. tridentata)/\mnchgrd^s, which is
dominated by Wyoming big sagebrush (A. t.
icyomiii^,cnsis), rabbi tbrush (ChnjsotluDnuus
spp.), bluebunch wheatgrass {A<i,r(>i)yn>n .spica-
tiitn), and Sandberg's bluegrass {Poa san(lher<i,ii);
(2) stiff sagebrush (A. n^'i<^/ft)/Sandberg's blue-
grass; (3) altered big sagebrush/bunchgrass,
which contains substantialK more bare ground
and lesser amounts of shrub and herbaceous
co\er because of repeated disturbance; (4)
grassland, predominantK bunchgrasses with
some rabbitbrush but xirtualK devoid of sage-
brush because of freciuent fires; and (5) ripar-
ian, with willow {Salix spp.), currant (Ribcs
spp.), grasses, sedges (Carex spp.), and Baltic
rush ijiinciis halticus).

M ETHODS

We captured Sage Grouse hens using spot-
lights and walk-in traps (Giesen et al. 1982,
Schroeder and Braun 1991) and fitted the
birds with numbered aluminum leg bands and
necklace-attached radio transmitters during
March 1992 and 1993. Each year, when radio-
telemetry monitoring confirmed nesting com-
pletion, fate was determined b\- inspection of
eggshell membranes or, in 3 instances (2 in
1992, 1 in 1993), observations of hens with
young. Initial brood sizes were estimated from
shells from successful nests, which were con-
sidered initial brood locations. We relocated
radio-marked hens with broods >1 time/wk
and attempted to obtain visual observations
without flushing either hens or broods. If
visual obsenations were not possible, we used
recent sign (i.e., droppings, feathers) as an
indication of habitat use. Each brood location
\\as determined with a global positioning s\s-
tein in Universal Transverse Mercator (UTM)
coordinates and marked with a flag to facilitate
relocation for measuring vegetation. A brood
was considered successful if >1 chicks were
obser\'ed with a radio-marked hen after 1
August, the approximate date when brood
integrity dissolves (Dalke et al. 1960, Oakleaf
1971). W'C used a t test to examine the null
hypothesis that mean brood sizes were the
same between years. Z tests with a continuity
correction (Zar 1984:395-397) were used to
test the null hypotheses that brood success rates
and coxer t\pe use were the same between
vears.

346

Great Basin Naturalist

[N'olunie 58

We examined 3rd-orcler (selection of coxer
types) and 4th-order (selection of particular
habitat components within cover types) habi-
tat selection by hens with broods (Johnson
1980). Availability of cover types (3rd order)
was determined within a composite minimum
convex polygon home range (Odum and Kuen-
zler 1955) from pre-nesting movements of
radio-marked hens with a geographic informa-
tion system. Availability for 4th-order selec-
tion was identified by measuring randomly
generated UTM coordinates within each cover
type from the composite home range during
the 1992-93 brood-rearing seasons.

We measured 4th-order characteristics of
hens with broods at brood locations and ran-
dom sites with 2 perpendicular 10-m transects
at each location; the direction of the first tran-
sect was determined randomly. Canopy cover
of all shrubs along each transect was estimated
following Canfield (1941). Cover of grasses,
forbs, and litter; residual cover; and bare
ground were estimated along transects with
ten 0.1-m- frames (Daubenmire 1959). Resid-
ual cover was defined as any dead upright
plant material and consisted primarily of Rus-
sian thistle {Salsohi kali), sagebrush, knapweed,
and tumble mustard {Sisymhriinn altissiminn).
Maximum height (cm) for shrubs and standing
dead vegetation and droop height (excluding
flowering parts) for grasses were measured.
Grass height was classified as short (<18 cm)
or tall (>18 cm) following Wikkinen (1990) and
Gregg et al. (1994). Vertical vegetation coxt'r
was measured at plot centers with a modified
Robel pole (Robel et al. 1970). Four readings
(2 each along the 2 perpendicular 10-m tran-
sects) were taken 4 m froiu the pole and 1 in
in height.

Separate analyses were used according to
brood age class: early (post-hatching-6 wk)
and late (7-12 wk). Previous research re\'ealed
changes in habitat use and diets of chicks at
approximately (i wk of age (Martin 1970,
Peterson 1970, Drul, (Jrawiord, and Circgg
1994). Both 3rd- and fth-order data in 1993
were apportioned into 3 diuiiial periods:
morning (0500-1000 li), midda\ (1001-1500
h), and evening (1501-2000 h). Too few broods
were monitored in 1992 to analy/e diurnal
habitat selection. Primary forbs in the diets ol
Sage Grouse chicks in Oregon (Drut, Pyle, and
Crawford 1994) and Idaho f Aiilcnriclh 19S1)

were combined and called food forbs for 4th-
order anaKsis. These forbs included milkxetch
{Astragalus spp.), clover {Trifolium spp.), hawks-
beard (Crepis spp.), microsteris (Microsteris
gracilis), and species in the Cichorieae (milk\'-
juiced composites). I^iparian and stiff sage-
brush/liluegrass cover types were combined
for 3rd-order analysis because of infrecjuent
brood use each year and were collectively
called "other. "

We compared cover t\pes used b\ radio-
marked hens with broods (observed) to the
availabilitv of each cover type (expected) with
chi-square analysis for 3rd-order analysis. If a
significant difference between use and axail-
ability was detected, Bonferroni simultaneous
confidence intervals were calculated to iden-
tify which cover types were used dispropor-
tionately (Neu et al. 1974, Byers et al. 1984).
The null h\potheses for 3rd-order selection
were (1) broods used cover tvpes during both
early and late brood-rearing periods in pro-
portion to their a\ailabilit\' and (2) brood loca-
tions b>' diurnal period were in co\ er t>pes in
proportion to their availability.

Null hypotheses for 4th-order anaKses were
that (1) brood and random measurements within
cover types did not differ, (2) there were no
differences between early and late brood-rear-
ing periods, and (3) there were no differences
among times of day and random locations.
rn)urth-order data were treated with anal\ sis
of variance (ANOVA) for unbalanced data and
protected least significant difference mean
separation tests (Proc Gl.M, SAS Institute, bic.
1989). Vegetation \ariables with nonuoniuil
distributions were translornietl ilogit transfor-
mation for proportional data and log transfor-
mation for height data); howe\'er. noutrans-
foiined means and standard errors are reported
herein. All statistical tests are 2-tailed and
considered significant at (X = 0.10.

Kist LIS

We caiitiHcd and litlcd S5 Sage (iionse
hens with ladio transiiiittci's dining Nhirch ol
bolh M'ars (15 in 1992, 10 in 1993); II
cliilclics were liatclicd in 1992 and 27 in 199:5.
Ivggs hatched from 22 .\[n\\ to 28 Nhiy in 1992
and betwciMi 2 Max and 19 June in 1993.
More tiiaii SO'^ of {Jiitclu'S hatched in the big
sagebnisli/biiiicligiass t\pe. Initial brood si/.e

1998]

Sacp: Grouse Brood Habitat Si:lectio\

347

Tabi.K 1. A\ailal)ilit\ and use (Vc) of'fo\'er t\pe.s l)\- Sage CIroiise hens willi hioods cluiiTig eail\ and late Ijiood-rearing
[H'riods on the Vakima Training Center, Yakima and Kittitas counties. Washington 1992-93.

.■\\ailal)ilit\

Biood-rearii

ig

locations Ci]

1992

1993

KarK

Late

EarK

Late

Co% er t\pe

Ci)

(;/•' = 22/5,

I

in = 7/4)

(ii -68/17

I 1

n = 24/10)

i^ig sagehnish/lnmchgrass

46

77+1'

71

68 +

38

(irasslaud

34

9-

29

24

58+

Altered big sagehrusli Iniutl

igrass

8

5

0

9

4

( Xliei-'

12

9-

0

0-

0-

■"ii = mirnlHr ol locations liroixis.

''+ = use tfrcater than i'Xi>ecti-d; no syrnhol = usi' in proportion to availabilitv ■

^Includes riparian and stil} sagt'linish/liluct^rass.

us<' less than expected /' < 0. lOi l)\ lionlt-rroiii conlidi-nct- intcr\a

T.\BI.E 2. .\\ailal)ilit\ and use (%) of cover t>pes by Sage Grouse broods during 3 diurnal periods. Yakima Training
Center Yakima and Kittitas counties, \\;ishington. 1993.

A\

ailabil

it\

M

orning''

MiddaN

Af't

ernoon

C()\ er t\pe

(%)

i;i =

= l.S/12|l'

(» = 49/15)

i;( =

= 25/14)

Big sagebrush/bunchgrass

46

67

65+^-

44

(irassiand

34

28

25

52

Altered big sagebriish/l)unc

hgrass

8

5

10

4

Other^

12

0

0-

0

"Moming (()5tX>-I0(MJ hi, niidda\ 1 1(H)1-1.500 h), afternoon ' I5()l-2(ll)(l In

"n = number of lotations/l)roods.

'^+ = use greater than e.vpected; no symbol = use in proportion to a\ailabilit\: - = use less than expected (P < 0.10) In BonliTroni confidence inter\als

'^Includes riparian and stiff sagebrush/l)luegniss.

was greater in 1993 Cv =7.1. s- = 0.42) than
in 1992 (.V = 5.7, .s- = 0.50, t = -1.8(1 P =
0.07). In 1992 only a single hen was known to
recruit \onng (3 chicks) into the August popu-
lation, hut at least 11 hroods {x = 1.5 chicks)
siir\i\cd to 1 August in 1993. Several radio-
marked hens entered a restricted area during
each summer and the fate of broods that
staxed in the restricted area (1 in 1992 and 4
in 1993) is unknown; consequentK, they are
not inchided in success estimates. An addi-
tional brood was removed in 1993 after con-
tact was lost with the radio-marked hen.
Brood success in 1993 was greater than in
1992 (10% in 1992 and oiWc in 1993, Z = -2.56,
P = 0.01).

We described 3rd-order selection by l:)roods
at 29 locations from 5 broods in 1992 and 92
locations from 19 broods in 1993. \o 4th-order
data were collected in 1992 because most
broods perished shortly after hatching. Fourth-
order data were collected from 72 locations
from 17 broods and 30 random locations in
1993. Brood locations in 1992 were not ana-
K zed b\ diurnal periods for 3rd-order selec-
tion because too few locations were obtained.

The mean time betw een location of a brood
and measurements for 4th-order characteris-
tics was 4.6 d.

Sage Grouse selected big sagebrush/l:)imch-
grass during earl\- brood rearing of each > ear
(Table 1) and used grasslands less than
expected during the earh' rearing period of
1992. No cover-type selection was detected
during the late rearing period in 1992,
although 71% of locations were in big sage-
l)rush/l)unchgrass. During the late rearing
period of 1993, broods selected grassland and
used big sagebrush/l)unchgrass in proportion
to a\ ailabilit)'.

During the morning period in 1993, broods
used all cover types in proportion to their
availabilit)' (Table 2), but at midday the\'
selected big sagebrush/liunchgrass. We foimd
no selection during the afternoon period; how -
e\'er, 52% of locations were in grassland.

In 1993 brood locations in big sagebrush/
bunchgrass had greater total fori) and food
forb coxer and lower shrub heights than did
random big sagebrush/bunchgrass locations
(Table 3). Brood locations in altered big sage-
brush/l^unchgrass had greater tall grass cover

348

Great Basin Naturalist

[V'olunie 58

Table 3. Habitat characteristics of Sage Grouse brood and random locations by co\ er t\pc on the Yakima Training
Center, Yakima and Kittitas counties, Washington, 1993

.\ltered big

Big sage

)rush/l)unc

igrass

sagel

rush/l)unchgi

ass

G

rassland

Brood

RandoTii

Brood

Random

Brood

Random

(;i = 43)

(u = 10)

P

(n ^ 5)

(n = 10)

P

(n = 24)

.V(.Vj)

(n = 10)
.v(.v^)

Variable

.v(.v^)

x(s,,

x(s^)

x(a-)

P

Shrul:) cover (%)

14(2)

20(2)

0.12

7(4)

12(3)

0.39

4(2)

3(2)

0.88

Shrub height (cm)

18(2)

25(2)

0.10

11(7)

14(3)

0.70

5(2)

4(2)

0.75

Grass co\er (9c)

Short, <18 cm

20(1)

20(2)

0.78

20(2)

19(2)

0.73

21(2)

23(3)

0.59

Tall, >18cni

17(1)

19(4)

0.7fi

21(6)

8(3)

0.04

21(3)

15(2)

0.24

Forb cover (%)

25(2)

8(1)

<().01

15(4)

21(6)

0.51

19(3)

14(4)

0.44

Food forb cover {%)

8(1)

2(1)

0.01

4(2)

3(1)

0.45

4(1)

3(1)

0.32

Residual cover {%)

1(0.2)

3(1)

<0.01

1(0.4)

1(1)

0.41

1(0.4)

1(0.5)

0.31

Residual cover height (cm)

1(0.3)

3(0.5)

0.03

2(1)

1(1)

0.77

2(0.5)

1(1)

0.24

Vertical c()\er height (cm)

15(2)

17(2)

0.26

17(4)

6(1)

0.01

9(1)

9(1)

0.94

Bare ground (%)

32(2)

35(4)

0..54

40(6)

49(4)

0.22

43(3)

47(5)

0.43

Litter (9c)

57'3)

60(5)

0.67

46^)

40(4)

0.43

44(3)

.37'5)

0.19

and taller vertical cover height than random
altered big .sagebrush/bunchgrass location.s.
No differences were detected between brood
and random locations in grassland. Food forb
cover was greater at earl\' and late brood loca-
tions than at random locations (Table 4).

Midday brood locations had greater shrub
cover and shrub height than morning and
afternoon brood locations (Table 5). Aiternoon
brood locations had less shrub cover and
height than random locations. Morning and
afternoon brood locations had greater tall
grass cover than midday brood and random
locations. During each diurnal period food
forb cover was greater at brood locations than
at random locations. Vertical cover was greater
at midda\ brood locations than afternoon
brood and raiidoiii locations.

Discussion

broods exhibited similai' ]xil(ciiis ol coxcr-
type use during the early rearing period each
year by selecting big sagebrush/l)unchgrass,
which also was the primary nesting habitat.
After hatching, before chicks can fly and wlu-u
moitah'l\ is highest (l^attcrson 1952, Auteiiricth
1981), broods need food in closi' pro.ximitx to
escape cover. Handom big sagi'brush/liimch-
grass locations had gicater shrul) toM r and
height than grassland and altcicd big sage-
brush/bunchgrass. .Short and tall grass cover
also was abundant in big sagebi iisli/bnnch-
grass. The combination ol sliiiib and grass

cover in big sagebrush/bunchgrass apparenth'
provided the best cover for nest success and
early brood survival on the YTC.

Most late brood-rearing locations in 1992
were in big sagebrush/liunchgrass, but in 1993
late brood cover-type selection switched to
grassland. Hens with chicks made greatest use
of grasslands during the afternoon period. In
Montana most early summer brood locations
were in sagebrush-grassland txpes, but as forl)s
desiccated, grouse shifted to black grease-
wood {Sarcobatus verrniculatus) and grassland
co\'er types in more mesic sites (Peterson
1970, Wallestad 1971). Saxage (1969) found that
broods left sagebrush uplands in Nevada din-
ing rapid temperature increases, which accel-
erated forb desiccation in sagebrush habitats.
Broods ma\' remain in sagebrush uplands when
free wat(>r is axailable oi' during years when
abundant [precipitation increases foil) a\ail-
abilitx (Oakleaf 1971, Dunn and Braun 19S(i).

I'buith-order anaKsis ol 1993 data suggests
that hens with broods in big sagebrush/l)unch-
grass ((■)()% of all locations) selecti\-el\ used
sites with more total lorbs (25'7 coxcr) and
more food fbrbs (iS'y comm) than a\ailabh' ran-
doniK (S*"^ and 2^^, respecti\el\). During I'aiK
and late rearing iieriods, sites with gri'atei'
anionnts ol ke\ lorbs wcic seleited. Shiiib
height and residnal eo\er were sliglitK less at
brood locations than at landom sites in big
sagebrusli/btnic-hgrass. In Oregon, Drut. P\le,
and Crawford (1994) foinid that total fori)
coNCiat brood sites, whieh langed Irom ll'/r to

1998]

Sage Ghoisi-: Brood II \Hri vr Skij-:ction

349

TaUI.K 4. I lal)ital tluuacteristics of Sage (Jroiist- hrood locations diirinu carK and lati- hrootl-rcaring jicriods and randon
locations on the Yakima Training Center, Yakima and Kittitas counties, Washington, 1993.

Variable

Earlv

(n = 53)

Late
(n = 19)

.r(.9,)

Random
(n = 30)

Shrub cover C/c)
Shrub height (cm)
(irass co\er {9c)

Short, <lScni

Tall. >lScm
Ibrb co\er (%)
K.i-y forb cover (%)
Re-sidual cover (%)
Residual cover height (cm)
Vertical cover height (cm)
Bare ground (%)
Litter ('"f)

ll(l,a,l,

14(2)

20(1)
19(2)

22(2)
6(1)A
1(0.3)A
1(0.3)

14(2)
35(2)A

52(2)

7(2)
9(3)

20(3)
18(3)
23(3)

6(2)A

0.6(0.2)A

1(0.3)
12(3)
39(3)A,B
50(4)

12(2)
14(2)

21(1)

14(2)

15(3)
2(1)3
2(0.4)3
2(0.4)

11(1)

44(3)3

4fi'3)

'Means witliiii row uitliuut leller-. or with llie saint' lettt-r arc not significantK diiltriTit i/' > 0.10;.
"Means within row with difierent letters are significantly different (P < 0.10).

\Y( (liirinii earl\ brood reariii"; and from 19'^(^
to 279f during late hrood rearing, influenced
e()\er-t\pe u.se. Likewi.se, Klebenow (1969),
Schoeniuirg (1982), and Dunn and Braun (1986)
found more fbrb cover at Sage Grouse brood
location.s than at random location.s. Relatively
low a\ailabilit\- of forbs in big sagebru.sh/
hunchgra.s.s apparentK* resulted in strong selec-
tion by broods for forb-rich areas within this
important brood-rearing co\er t\pe. Brood
locations in altered big sagebrush/liimchgrass
had greater tall (>18 cm) grass cover and verti-
cal cover than random locations within this
co\er type, suggesting that broods seek pro-
tectixe cover when using this less preferred
co\er t\'pe. No 4th-order \egetation selection
was observed for grassland brood locations
compared with random locations probabK
because forb co\er was sufficientK abundant
throughout and the abundant tall and short
grass co\cr likeK pro\ ided adeciuate conceal-
ment for escape.

Broods during midda\ selected big sage-
brush/biinchgrass and were obserx ed loafing
and dust-bathing under large sagebrush. Mid-
da) brood locations had greater shrub cover,
shrub height, and \'ertical cover than morning
and afternoon locations. Midda>' brood locations
also had greater vertical co\er height than
random locations. Several studies described
grouse loafing during the midda\- after morn-
ing feeding (Nelson 1955, Gill 1965, Savage
1969. Oakieaf 1971. Autenrieth 1981). Broods
used co\ er t)'pes in proportion to their axail-
abilitx during morning or afternoon periods,

but 52% of afternoon locations were in grass-
land, which coincided with e\ening foraging.
Morning and afternoon locations differed from
midday and random locations b\ having
greater tall (>18 cm) grass and less shrub
cover and height. Total forb co\'er and food
forb co\ er at brood locations were not signifi-
cantly different among diurnal periods. Dax-
time brood locations had greater forb and food
forb cover than random locations. Dunn and
Braun (1986) found that during the morning
broods fed in open homogeneous areas and
during the rest of the day used areas with
more horizontal cover and greater variation in
sagebiiish canop\' co\er to roost and ix>st. Sav-
age (1969j found that broods fed shoitK after
sunrise, loafed in sagebrush during midda>',
and moved to feeding areas in the evening.
Fourth-order location measurements during the
morning and afternoon suggested that broods
left dense cover to feed, but total and food forbs
were abundant at midday locations as well.

Late summer mean brood sizes from studies
elsewhere ranged from 2.3 to 3.9 chicks/hen
(Keller ct al. 1941, Patterson 1952, Nelson
1955, Saxage 1969, Wallestad and Watts 1973).
Although brood success increased significantK
on the stud\' area in 1993, the number of
chicks recruited/hen was lower than in other
studies and ma\ be insufficient to maintain
population stabilit\. Brood success was greater
in 1993 than in 1992, which probabK resulted
from weather conditions dining the 2 yr. .More
precipitation occurred in 1993, accompanied
by cooler temperatures that lasted into the

350

Great Basin Natlhaust

[\blume 58

Table 5. Hal)itat diaracteristics of Sage Grouse l)rood locations 1)\ dimiial period and random locations on the Yakima
Training Center. Yakima and Kittitas counties, NV'ashington. 1993.

Diurnal period''

Morning

Midday

Afternoon

Random

in = 13)

in = 39)

in = 20)

in = 30)

\arial)le

.v(.s-i

.v(.Sj)

.v(.v^)

x(sj,)

Shrub co\'er {%}

7(2)A,B''''^

15(2)C

4(1)B

12(2)A,C

Shrub height (cm)

9(2)A,B

18(2)C

6(2)B

14(2)A,C

Grass cover (%)

Short, < 18 cm

20(3)

19(1)

22(2)

21(1)

Tall, >18cm

22(2)A

16(2)B

22(3)A

14(2)B

Forb co\er (%)

21(3)

22(2)

22(4)

15(3)

Ke\' forb cover (%)

6(1)A

7(1 )A

6(1)A

2(1)B

Residual cover (%)

1(0.4)

1(0.3)

1(0.4)

2(0.4)

Residual cover height (cm)

1(0.4)

1(0.4)

2(0.5)

2(0.4)

Vertical cover height (cm)

11(1)A,B

16(2)B

9(2)A

11(1)A

Bare ground {%)

36(5)

36(2)

36(3)

44(3)

Litter (%)

51(4)

52(3)

52(4)

46(3)

aMorning (05()(I-I0(K) li). iiiidda>' (1001-1500 h), afternoon (1501-2000 h).

''M('an.s witliin row u ith diftc-rent li'tters are significantK different {P < 0.10).

"^Means within row without letters or w ith the same letter are not siKnitieantK different If > 0. 10;.

summer. Increased precipitation in Nevada
resulted in greater forb production, delayed
plant desiccation, and possibly enhanced juve-
nile survi^'al (Oakleaf 1971). Peterson (1970)
ioimd greater brood success during wet years
in Montana when forb production was 2-3
times that of dry years. Autenrieth (1981) noted
that migratoiy populations of Sage Grouse had
high brood success because they were able to
find forbs, whereas sedentary populations (like
those at the YTC) had good reproductive suc-
cess during moist years when forbs were
abundant but did poorly during dry years. An
increase in food and cover on the YTC in 1993
may have reduced brood movements, result-
ing in lower predator exposure and energetic
costs of foraging. Nevertheless, by 1 August
one-hall of the broods were lost and the
remainder declined from a mean of 7.1 to 1.5
chicks, approximately an 80% loss.

We concluded that nesting success (45%)
was rather typical for Sage (Arouse, but brood
recruitment to 1 August (14%) and, especially,
the number of chicks recruited (24 from 45 suc-
cessful hens during the 2 yr) were lai below
average. We suggest that brood-reariug habi-
tat was a strong hniitiug factoi" for this small
population. Our results indicated that big sage-
l)rush/l)unchgrass and grasslands arc impor-
tant cover types throughout brood rcaiing.
Within brood-reariug habilal, there was si'lec-
tiou lor sites with greater lorb cover, especialK
loibs used as food, and sin iib or grass coxci" (lor
concealment). Unlike niaii\ other Sage ( iioiise

populations in western states, hens did not have
the choice of alternative high-quality brood-
rearing habitats, such as low sagebrush (A.
arhusula), meadows, lakebeds, or broad, forb-
rich drainages. Lack of these critical cover
types at the YTC coupled \\ ith existing habitat
conditions likeh' had an adverse effect on
recruitment, which ma\' limit populations on
the YTC.

Ackno\\leix;ments

This stud\ was iunded b\ Pacific North-
west Laborator>' under a contract with the U.S.
Department of l^efense (I3013). J.A. l^labon,
T.M. Kollasch, M.A. Lacroix, A.W. Learx, and
K.D. Hand assisted with data collection. W'e
thank L.L. Cadwell and the late P.E. Eber-
hardt for logistical support and liaisons with
1)()D. M.A. Gregg pro\ ided xaliiable coininents
on the mamiscript. This is inainiscri[it 1 1,112 of
the Oregon .\grieiiltiiral lv\piMinient Station.

Uni'iaii Ki". (;iTi:n

Al'TI'.MUl I II, IMv 19SI. Sage (Irousc niaiiagcnicnl in
Idaho. Idaho Di'paitnicnl nl I'isli .iiid (iaiiic Wildliic
Bulk'tin 9. 23S pp.

HiHCKlU 1), A.T 19(ScS. I^opulation ecologxol Nortii Aiiicri-
can grouse. Pages 578-685 in \.'\'. Bergcrud .nul
\I.^\■. (iralsdii. cdilors, .\dapti\e strategies and poi)-
nl.ilinn (■coidt^N ol northern grouse. L!ni\t'iNit\ oi
Minnesota I'ress, Miuni-apolis.

Hm lis, (,'.R., R.K. SrKiMioHsr, wn \'.\\. kn\i s\i\\. 19S4.
( ,'l.irificalion ol a teehnitiue lor anaKsis ol utili/.a-
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incnl lS:l(r,() K^.

1998]

Sack Ghoi sk Bhood Habitat Ski.kctiox

351

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metliod ill saiiipliiiij ot range \x"getati()ii. Journal ot
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Daiki:, RD.. D.B. Pmuii, D.C. Stanton. J.E. Chaw i-orix
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Gil:si;n, K.M.. T.J. Sc:ii()i:nbl;r(;, and C.E. Bhaia. 1982.
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Gill, R.B. 1965. Distribution and abundance of a popula-
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Received 5 February 1997
Accepted 24 November 1997

Great Basin Naturalist 58(4), © 1998, pp. 352-362

SOIL-VEGETATION RELATIONS OF RECOVERING
SUBALPINE RANGE OF THE WASATCH PLATEAU

James O. Kleniniedson' and Arthur R. Tiedeniann-

Al!STHAt:T. — On degraded suhalpine range of the Wasatch Plateau, we examined the hvpotliesis tliat ree()\er\ of \eg-
etation, as manifested by its composition and l)ioniass yield, was related to soil phosphorus (P) and suHur (S^ status. We
sampled 6 topographic locations to determine the relationship among composition and \ield of grasses and forhs, litter
cover, and soil characteristics including rock cover, organic carbon (C„), total N (N,), available nitrogen (X.,^), total phos-
phorus (P(), organic P (P,,), inorganic P (Pj), total potassium (K), total S (S,), and element ratios. We also evaluated aspect
effects. An alternati\e hypothesis was that productive potential was a function of depth of soil remaining after the period
of destructi\'e grazing. Differences among locations were significant for all \egetal attributes and for all soil characteris-
tics except total K and C^. Aspect was significant onK- for forb yield and Pj. Regression coefficients for \ ield and per-
centage composition of grasses were always opposite in sign to those for forbs. Yield and composition of grasses and
forhs as groups were oppositely and strongly related to soil element ratios of C,/P,, N/P„, C„/P(, and C„/S( but were not
related to soil P( or Sj. There was no clear support for acceptance of the hypothesis that soil P and/or S were major fac-
tors in recovery of this suhalpine range after destructive grazing. Differences in regression coefficients and lower r-\ al-
ues among species within grass and forb groups, than for the groups themselves, to soil variables is a reflection of
species individuality. This indicated a need to examine soilAegetation relationships at tlie species level. Percentage com-
positions of grasses and forbs were oppositely related to the depth of A -I- B horizon, lending support to acceptance of
the alternative hypothesis.

Key words: .suiniiwr range, plant comixisition and cover, herbage i/ield, litter, soil C, \, P, S, and K.

After 35 years of destructive grazing b\' cat-
tle and sheep in the late 1800s, the suhalpine
range of the Wasatch Plateau east of Ephraini,
Utah, was in poor condition (Reynolds 1911,
Sampson and VVeyl 1918, Sampson 1919).
Depletion of vegetation reached such severe
proportions that most of the soil A horizon was
lost by erosion and nnid-rock floods were a
common occurrence in the canyons and val-
leys below (Reynolds 1911, Croft 1967). In
many places only subsoils remained when
grazing regulation was begun with the 1903
establishment of the Manti National i'orest
(Reynolds 1911, Sampson and \Ve>l 1918, Flli-
son 1949). Transient Hvestock herds were abol-
ished and livestock nimibers greatly reduced,
but most of the summer range was so badly
deteriorated that these management changes
were insufficient to halt contimiing soil loss
(Ellison 1954). Although condition of the range
improved over the next 4 decades, most of the
suimner range was still unstable in 1950 and
accelerated erosion was continuing, but at iiuicli
reduced rates (Ellison 1954, Meeuw ig 19(i0).

Our obser\"ations suggest that impro\ement
in soil and vegetal conditions reached a plateau
about 1930-1940, based on Ellison's (1954)
lecords, and has remained essentialh' the same
from the time of Ellison s studies (Intcrmoim-
tain Kesearch Station, Prcno, Utah, impublished
data; lohnson UJW). These obsei'xations led us
to ask why, after 30-40 \r of rapid improx t'un'ut
imder reduced grazing pressiu'c, should si'c-
ondary succession apparently stabilize at a niid-
seral stage and remain so imtil the present:'

There are perhaps several possible explana-
tions for the apparent stable state (Lewontin
1969, l.a>cock 1991) that tvxists on the Wasatch
summer range. I'wo explanations (K'lixc cliii'lh
from degradation of the ccosxstem and massi\ c
erosion that occurred over the long period ol
lix'estock overgrazing: (1) loss ol nu)st ol the
soil A horizon and hence nu)st ol the soil
organic matter and nutiient capital, and altei-
ation ol nutrient e\cling processc\s (Nikiloioll
1959, Antlerson 1988); (2) loss of extinction-
prone perennial grasses (Mack and Thoiiipson
1982, O'Connor 199U which arc tlic kc\ climax

'SchcKiI of Renewable Natural Resources, .32.5 HioloKieal SeieiKcs East BuildiiiK. I iiivcisity i>r.'\i'i/.(>ua. TuiMm. .\Z .S.572I.
^Pacific Northwest Research Station, 1401 Cekeler Lane. UiCraride, OR y78.'5(). Corrcspondinn author.

352

1998]

S()ii.-Vi-:(;ktal Rkl\tions of Recoverinc; Sibalpink Range

353

tlomiiumts in siiiiilai' suhalpinc landscapes
tliroiiuliout the West, and were tlioutilit 1)\
Sampson (1919) to ha\e dominated the pris-
tine vegetation here.

Altliouiih lM)th e.xphuuitions for the appar-
ent static conchtion ot soil-plant s\stems on
thi' Wasatch summer range have merit, wf
locus on the former in this paper. More specil-
ically, we h\pothesized that losses of soil phos-
phorus (P) and/or sulfur (S) following the
period of destructi\e grazing and erosion have
diminished le\els of one or both nutrients to
the extent that accumulation ot organic C and
\ to pre-degradation le\ els has been impeded
(Walker and Adams 1958, Cole and Heil 1981).
This in turn has limited soil development dur-
ing range recovery. An alternative hypothesis
\\as that neither P nor S was limiting relati\e
to other elements, but that soil loss was so
extensive that productixe potential is now
largely governed b\' the amount of remaining
soil (i.e., A and B horizon). Under either hy-
pothesis, regaining climax conditions of the
former ecosystem would seem to require soil
formation oxer a xerx' long time to reestablish
the original steadx-state soil profiles character-
istic of the pre-187() clima.x soil-plant-nutrient
sx'stem (Olsen 1958, Jennx- 1980).

Study Area

ous shales with minor inteibeds ol sandstone,
oil shale, eonulomerate, g\psum, and xolcanic
ash (Weber 19(i4, .Schreiber 1988). Soils of die
plateau are nioslK line, mixed argic Cry-
oborolls, but lithic, pachic, and \ertic Crx-
oborolls also are present. Thc\' arc shallow to
modi'iateb deeii: subsoils are silty clays or
cla\ loams. I liickness of the A horizon aver-
ages just 4 cm: that ol the B horizon axerages
52 cm (range 30-74 cm). Based on t\pical
profile descriptions (H.K. Sxvenson, Natural
Resources Conservation Service, Boise, ID,
personal communication), these relatixe hori-
zon thicknesses indicate that much of the orig-
inal A horizon was lost b\ wind and water ero-
sion following the period of unrestricted graz-
ing prior to 1903.

Vegetation of the \\'asatch Plateau is chiefly
herbaceous, but patches of Engelmann spruce
{Picea engelmannii) and subalpine fir {Abies
lasiocarpa) occupy steep northerly exposures
of east-west ridges and dot the plateau land-
scape. Because remnants of pristine vegeta-
tion do not e.xist (Ellison 1949, 1954), opinions
differ regarding its exact character. Ellison
(1954) described the original herbaceous com-
munity as mixed-upland herb dominated by
tall forbs, xvhile Sampson (1919) considered
xvheatgrasses {Agropyrnn spp.) the priman' cli-
max dominants.

The studx' area is centrally located on the
Wasatch Plateau about 17 km east of Manti,
Utah. The area extends south 7 km from near
the Alpine Station along Skyline Drixe (Road
139) to Snox\- Lake. The long, narrow plateau
is oriented approximatcK north and south with
riblike ridges extending east and xvest. The
plateau top is gentlx' rolling, but gradient steep-
ens (up to 65%) on slopes of east-xvest drain-
ages. Average annual precipitation is about
840 mm; 2/3 of this falls as snoxv betxveen
November and April. Precipitation axerages
173 mm during summer months (June through
September) but xaries considerabK. Mean
annual temperature is about 0°C (Ellison 1954).
During the growing season (Max' through
October), ax-erage maximum temperature is
21°C; axerage minimum is -5°C (Ellison 1954).

Soil parent materials are of the Flagstaff
formation (Stanley and Collinson 1979) that
outcrop over about 7200 km- in central Utah
(Schreiber 1988). The dominant lithologx- is
freshxvater lacustrine limestone and calcare-

Methods

The original strategx' for testing the hxpothe-
ses xvas a comparatixe analxsis of paired eroded
and uneroded soil-plant systems at various
locations. However, after an exhaustixe search,
it xvas apparent that grazing use of this sum-
mer range had been so complete during the
period of dex astation that uneroded sites were
nonexistent, even on plateaus isolated by steep
terrain that we believed xvould limit access to
livestock.

Instead, we selected 6 topographicalK' sep-
arated locations, mostly small knolls, and sam-
pled soil and plant attributes on up to 4 aspects.
All 6 locations had a similar grazing historx'
until the 1930s. Since then Elk Knoll (EK) and
Alpine Cattle Pasture (CP) haxe been pro-
tected from livestock. Ideally, this xvould give
us an array of site conditions that xvould per-
mit differentiation among locations and aspects
based on soil, parent material, and xegetation
properties, and permit determination of key

354

Cheat Basin Natur-xust

[Volume 58

variables influencing; herbage composition and
production on the summer ranj^e.

On each location we attempted to restrict
aspect sampling points to a single parent mater-
ial stratum; hence, elevation among aspects
was near constant. However, this was probably
futile. Because individual parent material strata
were usually very thin (<().5 m; Klemmedson
and Tiedemann 1994), there was little confi-
dence in sampling the same parent material
among all aspects of a location. All locations
were within 7 km of each other. Northeast,
SE, SW, and NW aspects were sampled on
Elk Knoll (EK; elevation 3116 m) and a knoll
adjacent to Snow Lake (SL; elevation 3133 m).
Two aspects were sampled on Trail Ridge (TR;
elevation 3216 m). Skyline Drive (SD; eleva-
tion 3200 m), and Alpine Cattle Pasture (CP;
elevation 3066 m); a single aspect was sam-
pled on South Knoll (SK; elevation 3109 m).
Slope gradient was 10-30% among aspects on
SL; gradients were <5% on other locations.

We sampled at selected aspects from ran-
domly located soil pits and vegetal-litter-cover
plots. Soil pits were dug and profiles described
by standard terminology. Single samples of
known volume were taken from each horizon
(3-5 above the C or R horizon) for laboratoiy
analysis, lierbage and litter were sampled in 6
randomly located 0.5-m2 plots near each pit.
Basal cover of litter, bare ground, and rock,
and foliar cover by species were visually esti-
mated; mass of grasses, forbs, and litter was
determined by harvesting each component
separately, followed by oven-drying (7()°C)
and weighing.

For chemical analyses we air-dried soils,
sieved them to remove the >2-mm fraction,
and then ground them to pass a 150-|im sieve.
Samples were anal\ zed for total C by dry com-
bustion (Nelson and Sommers 1982) in a
LECO high-fre(jucnc\' induction furnace
(LECO Corp., St. Joseph, Ml). Organic C {CJ
of soils was determined b\ difference after
determining carbonate b\ a gasometric
method (Dreimanis 1962). Total N (N,) was
determined by semi-micro-Kjeldahl (lirenuicr
and Mulvaney 1982) and total S (Sf) !)> di\
combustion in the IA\CX) high-fre(juenc\
induction liuuace Criedemann and Anderson
1971). Total soil P (1^() was determined using
ascorbic acid color devilopincnt (Olscn and
Sommers 1982) following h\ (Irolluoiic acid

digestion (Bowman 1988). Inorganic P (Pj) was
determined with the same color de\ elopment
on samples ignited at 550°C for 2 h (Olsen and
Sommers 1982), while organic P (P„) was
determined b\ difference. Available nutrients
(X.^^.) were determined as follows: P by ascor-
bic acid color development following 0.5 M
sodium bicarbonate extraction (Olsen and
Soiumers 1982), N by steam distillation of 2 N
KCl extracts (Keeney and Nelson 1982), and S
with 1:1 water extracts, followed by ion chro-
matography (Dick and Tabatabai 1979).

To facilitate comparison among sites and
aspects, we summarized soil horizon data and
expressed the data for the 0- to 15-cm soil
layer and for the entire solum. The data were
analyzed by 2 ANOVAs: 1 for EK and SL kniolls
with data for all 4 aspects, the 2nd with data
from all 6 locations, where the number of
aspects sampled was unequal. In the latter
ANOVA the interaction term was calculated
using data only for EK and SL locations. Back-
ward (stepwise) multiple regression analysis
was used to relate herbage \'ield and composi-
tion to soil surface and 0- to 15-cm soil la\er
properties.

Results and Discussion
Location and Aspect Differences

Vegetation and soil co\ er. — AnaK sis of
variance for all locations showed significant
differences among locations for 6 attributes of
vegetation and cover at the P < 0.05 level
(Table 1). Of these, forb yield was the onl>'
attribute that also differed significantK- among
aspects (Table 1); it was highest on NW aspects
and lowest on NE and SE aspects (Table 2).
The signiiicant location response of forb com-
position (by foliar co\er) nuist be (jualified
because oi the significant Location x .\spect
interaction (Table 1). f'orb composition re-
sponded differeulK to aspect at EK and SL
locations, especially on SE and SW aspi'cls
(Table 2). This response ma\. at l(\ist in pait,
be influenced b\ parent iiuitcrial at the SL
location. In a companion slucK (Klenunedson
and Tiedemann 1998), parent niafi'iial was
highly associated with \cgetal pioperties.

Based on \aluc>s for the (i \c'getalion and
c()\(M" attributes discussed abox f, thi' locations
appear to lorni 1 distinct groupings (Fig. 1).
I'lic l',K, (.1! and Sk locations wcie sinu'lar for

1998]

Soii.-Vkcki \i Rii vi IONS oi" Rkcon KHi\(; SiHALPiNK Range

355

TaBII I. I'iiil).iliiljl\ values Iroiii aiKiKsis ol \ariaiKr lot all imatiiiiis, and l(ii I'lk Knoll ! I" K ) and Snow l^akc (SL)
locations alonr.

Probability \alnes

.\11 locations

EK and SL

Nariahk's

Location

.Aspect

Lx.\

Location

Aspect

Nkckiation and si'Ri'Ac:t:

(xniCK

Total \ielcl (g/m2)

0.033

NS

NS

NS

NS

Forb \ielcl (g/ni-)

< 0.001

0.038

NS

0.004

NS

Grass composition (%)

0.036

NS

NS

0.090

NS

Fori) composition (%)

0.034

NS

0.050

0.090

NS

Bare s^round {7c)

0.006

NS

\S

\S

NS

Kock co\er (%)

0.029

NS

NS

().()()4

NS

Si'RrAc:t; soil, 0-15 cm

Organic C (kg/m-)

0.071

NS

NS

0.053

\S

Available N (g/m^)

< 0.00 1

0.099

NS

NS

NS

Total P (g/m2)

0.009

0.010

NS

0.002

0.049

Inorganic P (g/ni-)

0.010

0.069

\S

0.013

NS

Organic P(% of total)

0.013

\S

0.010

0.047

NS

Total K (kg/m2)

NS

NS

NS

0.019

NS

Co/P,

0.004

NS

NS

().()()5

NS

c,ys,

0.007

NS

NS

0.001

NS

N,/P,

<0.001

NS

NS

0.001

NS

N,/P„

0.002

NS

NS

0.138

NS

Tabi.l: 2.

nflniMice of aspect on fori

) \ ield. and

inti

raction ol location and aspect on forb compositioTi In fol

ar co\ er.

.'Vspect

NE

SE SW NW

LSD*

i'orb \ield (g/m-)

Forb composition {%)
Elk Knoll
Snow Lake

67
61

76

84
53

98

87
28

128

90

24
17

conipo.sition of grasses and lorhs, less so for
eoxer of bare ground and roeks, and differed
in herbage yield (Fig. 1). Yield of forbs and
total herbage for the EK and CP locations was
siniilan and much greater than that for the SK
location. Herbage \ield at all 3 locations was
dominated by forbs (>80% of yield and com-
position). These locations had little exposed
rt)ck {<5%) and moderate amounts of bare
ground (13-2670.

The SL, TR, and SD locations form the 2nd
group. They were similar to each other for
most attributes, especialK > ield of forbs and
composition of grasses and forbs (Fig. 1). The\-
had significantK lower total herbage yield

than the EK and (;P locations and xi-getal
composition was about ecjualK di\ ided between
grasses and forbs. These locations (SL, TR,
and SD) all had large amounts of bare ground
and exposed rock (Fig. 1).

The 6 locations break out into the same
groupings based on species composition. Of
the 25 species comprising at least 3% of the
composition (Table 3), only 2 grasses {A^ropij-
roii trachijcaulwn and Stipa Icttennani) and 1
fori) {Achillea millefolium) occurred on all 6
locations. Composition of these 3 species was
similar among the SL, TR, and SD locations,
and from 2.0- to 6.6-fold higher than that for
the EK, CE and SK locations. The 2 groups of

356

Cke.vi- Basin NATUiuLibX

[Volume 58

CN

250

200

\ 150
CD

12 100

>-

50

0

100

S? 80

o

Q.

O
O

^?

Q>
>

O

o

[ZD Total

Forbs

i-

60

dZ! Grass ^ Forbs

1

ll

1

^° r IZZ) Bare Ground CIZ3 Rock

45

30

I ^

I
$

4_

EK

SL

TR SD CP

Location

SK

Fij^. 1. Kflcct of location on yield ol lorhs and total xciie-
tation, coinijosition (l)y loiiar cover) ol ^rassi's and lorhs,
and coxcr ol hare j^roiind and rocks.

300

<N 240
E

180

120

[ZZI Total P ^ Inorganic P
1

^° 30

12

nn C^^g, kg/m^
^Nq^. g/m2

i^

SL TR SD CP

Location

SK

FiK. 2. Effect of" location on amounts oltotiJ and inorganic
1' percentage organic P and amounts of organic C and
a\ailal)le N in soils.

locations al.so differed in distril)iiti()n ol scx-
eral forl).s. Six species {Aster foliacc us v. canhiji,
ErU^cron speciosus, Geranhnn jnnnontn, Lu^iis-
ficuin portcri, Pcnstemon ry(lh('r<i,ii, and Poten-
tilla (gracilis) were foinid only on the EK, Cl^
and SK locations (at least 2 of the 3 locations),
while 2 species (Artemisia hi(l<>riei(nui v. in-
coinpla and (Ujiiioplenis leiiimonii) oecm-red
oiiK oil the Si\, T\\. and SI) sites (Table 3).
In a eonipanioii study on llie SL location
(Klennnedson and 'riedcinami 199S), ('. lein-
iiionii was highly associated with roekx sites
with shallow soils ol low nutrient eoiiteiit.

Son, l'IU)l'i;nrii;s. — Nine propcities ol the
0- to 15-eiii soil hiNcr dillered siirnilit aiilK

anion^ the (i locations (Table 1). nilliMiMices
were sipiificant at the /' < 0.01 le\i'l tor N.,,.,
F,, Fj, and the C./Pt, C;„/S,, and N(/F, ratios, at
the P < 0.05 le\el for percentage I'.,, and at /' <
0.10 for (],,. in the case of F,, content as a per-
centage of F|, tlu're was a signilicant L X A
inti'iaction (Table I): F,, was niarketlK higher
at the \']K than the SL location for all aspects
except SW.

Kesiilts ol till" anabsis of \ariance lor EK
and SL locations alone (Table 1) wen- similar
to that lor all locations, with 2 exceptions.
These 2 locations did not diller signiliiantly in

998]

S()ii.-\'i:(;i:r\i. Hki.ations of Rkconkhinc Si bai.hink Hwce

357

TaBI.K 3. Species (.■oinposition i'( i at <i kiioll locations''

Knoll

location''

Negetal loiniioncnt

i-:k

SI.

111

SD

V.V

SK

Giussi:s ANDGiussi.iKi:

Afiroptjroii traclujcdiiluiii

7.6

10.5

13.1

8.9

3.6

3.4

Alopccuru.s [mitcn.si.s

3.4

Carcx inur()})tcra

3.6

Stiixi cohiinhianti

6.7

Stiixi Ivttcnnani

3.8

28.2

30.5

36.6

5.2

6.0

Otlurs

3.2

1.0

0.6

2.7

3.0

0.8

Total

18.2

4(x 4

44.2

48.2

11.8

13.6

FOKHS \\l) SlIKLBS

Achillea iiiillcfoliiim ssp. hiniiliisa

S.4

12.6

15.0

n.3

5.8

5.6

Artciiiisid ludnviciana \. iiicoinpta

LS.S

4.7

19.7

Aster foliacc lis \. canlnji

13.6

Astragalus miser \. ohlon^ifuliiis

3.0

Castilleja sulphurea

4.6

5.2

Cijinopteni.s leininonii

5.2

9.8

10.6

Erificnnt si)eciosus

5.3

4.9

3.4

Erii^cnm iirsinus

8.2

Ceratiiiiin frcinontii

13.5

22.4

Lescjuerclla iitatieiisis

3.3

Li<lti,stieuin porteri

5.2

8.2

Peiisteinon rydher^ii

10.9

4.4

3.6

Potent ilia dandulosa

3.4

Potentilla gracilis

3.1

10.8

Solichifio parnji

.55.2

Sweiiia perennis

3.0

Taraxacum officinale

4.6

6.5

\ (deriana occidentalis

4.2

3.6

Vicia americana \. amcricana

6.4

4.6

Vicia iiiittallii \. mtttallii

5.8

Others

18.8

6.0

5.2

6.9

12.6

9.8

Ibtal

81.8

58.6

55.8

51.8

88.3

86.4

^Based on toliar cover; species with <3'* composition not listed.
■'See text for names and descriptions of locations.

N.,^, hut tlie\ did differ in total K. Moreover,
there was a signifieant L x A interaction for Pj.
Although Pf was higher at SL than at EK (Fig.
2), the absolute and proportional differences
were a finiction ol aspect.

For soil properties, the 6 locations did not
break out into the 2 groups observed for vege-
tation and co\er attributes. Those groupings
were apparent onl\' lor 1 of the 9 soil proper-
ties (Cg/Pt ratio) found to differ among loca-
tions (Fig. 3). Anal) sis of data for \ariables of
tlic entire solum added \vr\ little information
to that shown for the 0- to 15-cm soil la\ er and
hence are not shown here.

Vegetation- Soil Relations

The marked differences described abo\ e in
vegetal attributes and soil properties among
locations caused us to pursue further soil-\ eg-
etation relations that might explain vegeta-

tional differences among locations (Fig. 1,
Table 3) and give clues to the serai plateau
these systems have been in for the past 50 yr
Simple linear regression relating vegetal
attributes with soil properties, especialK' diose
shown to be significant in Table I, indicates
that grasses and forbs, as groups, responded
differentK; but consistentK; to these \arial)les
(Table 4). In fact, for each independent \ari-
able shown in this table for regressions with
herbage yield and composition as dependent
\ ariables, the regression coefficients for grasses
were always opposite in sign to that for fbrbs.
C>ertainly, this was not the case for all inde-
pendent variables we sampled, but for the
large majority' the trend was \ er\' noticeable.

In a companion stud\' at the SL location
(Klemmedson and Tiedemann 1998), the dom-
inant grass {Stipa lettennani) and forb [Cytnop-
tenis lemmonii) were oppositely related for

358

GuE.vr B.\siN N.\i L lULisr

[Volume 58

200 r CZDCyP,

IS9 cys,

150

N^/P, X 10

TR

SD

Location

Fig. 3. Effect of location on elemental ratio.s of soil.

every variable sampled. But, for groups of
grasses and forbs comprising many species
(Table 3), it is remarkable that these groups
would respond in an opposite manner so con-
sistently to various growth (soil/site) parame-
ters, although not always with high /--Nalues
(Table 4). That correlation coefficients associ-
ated with specific independent variables in
Table 4 were not high, as a rule, is a reflection
of the individuality of species within grass and
forb groups in response to location and aspect.
Ingure 4 illustrates this indi\idualit\- of 2 grasses
and 2 forbs in their response to Co/Pf and
C^/Sf, variables that were both highly corre-
lated with grass and forb composition (Table 4).
Contrasting responses of grass and forb groups
also have been observed by Huenneke et al.
(1990) in short-term fertilization experiments
on seipentine soils. Within vegetal groups hav-
ing common properties, species responded to
experimental treatments in an iudixidualistic
manner. Also, Chapin and Sha\cr (1985) ob-
ser\cd this kind of species-connnimity beha\'-
ior in response to nianipiilation ol enx ironnicnt
in tundra.

Ol those \arial)lcs one would ordinarily
associate with soil leitility, only C.\, and the 2
element ratio xariables were correlated with
yield aiul (■()in|)()siti()n (Table 4). \']\v high /-
values lor percentage litter cover and rock
cover are at first pu/./ling. However, when one
considers the extent ol eoiiclalion nsiialK
f)bser\cd among soil-plant-litler pro|)eities,
l)()tli positively and negatively, high r-\alnes
lor soil surface variables (I'able 4) are not sui-
prising. Moreover, these soil smface variables
may be expressing the influence of soil plnsi-
cal properties that we did not sample, but

ii)

O Cyle. r = -0.71
• Gefr, r = 0.52

•

20

•

o o

•

•

10

o .--■'''

<^

•
o

0

• • m •

— e —

•^d"G^ o

a

80 100

^org/Sf I'a+io

o Agtr, r = -0.33
• Stie, r = -0.61

Fig. 4. Relation.ship of composition (1)\ foliar co\er) of
Cijinoptcnis Icintiionii and Geranium frcinoiitii to C„/S( ratio
and composition of A^^rojuiwu trachijcaiiluin and Stipa Ict-

IcniKiiii to (',,/F, ratio.

which may haw significantK inllueneed \ege-
tal yield and composition.

Table 5 siunmarizes our attempt to predict
herbage \ield and composition \\ ith 2-\arial)le
equations using backward multiple regression.
0\'erall, percentage rock coxer was the most
efficient predictor of \ield and composition of
both grass and forbs, based on standardized
regression coefficieuts. Percentage littcM' co\er
and bare ground were about e(iiial as predic-
tors ol total \ield. P,, was as elficieut as soil
surface features onK in the grass \ ield i'(jua-
tion. When a 3i"d xaiiabli" was allowed in the
e(ination (3-\'ariable ecinations not shown), I',,
filled that role in 4 of 5 cases, based on varia-
tion explained. In tlu' 3-\ ariable grass \ ield
e((uation, (],, beeanic the 3rd and most efficient
\ ariable. That \aiial)lcs poitraying soil surface
leatnres would appear as the most effieient
predictors ol xcgelal \ ield and eomi)osition in
ninltiple icgression is not surprising in \ iew of
results from simjile regression (Table 1) and
suggests a high degree of intei'corrt'lation with
soil propcities nioic eoinniouK associated w ith
|)iodneti\ it\.

1998]

S()ii.-\'i:(:i:i"\i. |{i:i.ati()\s of Kkcomihinc Siiulpini-: Ranci-:

359

I'aBI.i: 4. (!()ii trust iiii; rt'tircssion iclatii)iis Ixlwccn \ icid .iiid (.oiiiposilioii iil 'grasses and l(>il)s and si'\t ral iiidrpi'iulciit
ariabk's.

Regression

coeHicient

Correl;

tion coellicient

l)t'[i('iuli'nt

Indt'prndnit
\arial)!i's

\aiiaI)U'S

Crass

Forhs

Cra.ss

Forhs

Vii'ld (g/ni^)

Organic C (g/ni-)

-7.176

25.158

-0.43

0.68**

Total \ (jVm-)

-().()9()

0.234

-0.30

0.40

Total P (g/m^)

0.146

-0.416

0.27

-0.40

Total S (g/m^)

-0.431

0.799

-0.25

0.24

c,yp,

-1.273

2.895

-0.63*

0.73**

N,/P„

-6.627

14.116

-0.64*

0.67**

Rock cover (%)

3.356

-9.188

0.58*

-0.81**

Litter cover (%)

-0.051

4.123

-0.13

0.76**

Composition'

Organic C(g/ni-)

-5.993

5.940

-0.54*

0.54*

Iota! \ (g/ni-)

-0.079

0.076

-0.49

0.49

Total P (g/ni^)

0.087

-0.092

0.28

-0.29

Organic P (g/ni-)

0.435

-0.449

0.42

-0.43

CVP,

-0.881

0.890

-0.74**

0.74**

Co/s,

-0.820

0.830

-0.69**

0.70**

Rock cover (%)

2.686

-2.7.54

0.79**

-O.SO**

'Signiticant at P < 0.0.5.
»*Significantat/'<0.01.
*Based on foliar cx)vfr.

IvULK 5. Statistics ironi hackward nmltiple regression predicting herbage \ield and composition (hased on loliar
co\er) \\ ith 2-\arial)le ecjnations.

fi-s(|iiare

0.72

Herbage

Standardized

Probabilit\ of

comi^onent

N'ariables

coefficient

significant F

YlF.I.i)

Total

Regression

0.002

Litter co\ er

0.238

0.001

Bare ground

-0.216

0.067

Crass

Regression

0.026

Rock co\er

0.493

0.024

Organic P

0.454

0.085

Forbs

Regression

0.001

Litter cover

0.408

0.001

Rock co\ er

-0.553

0.021

Composition

Crass

Regression

0.007

Litter cover

-0.094

0.016

Rock co\ er

0.730

0.015

F^orbs

Regression

0.005

Litter cover

0.092

0.013

Rock co\er

-0.744

0.012

0.52

0.76

0.63

0.64

We demonstratt'd stronti; as.sociation Ix'tw t'cn
grass- versus forb-doininated vegetation and
several soil nutrient and sviifaee soil properties.
On the whole it appears that torbs responded
positively to variables generalK assoeiated
with better growing conditions, and the oppo-
site for grasses. Moreover, results demonstrate

marked differences among the 6 study loca-
tions based on these soil-plant relations.
Although vegetation was strongly associated
with K and to a lesser extent S, it seems pre-
mature to accept the priman h\podiesis regard-
ing the importance of P and S. The opposite
relationship of grasses and forbs to depth of A

360

Great Basin Naturalist

[Volume 58

O Grass, r = 0.50 • Forbs. r = -0.51

00

•

80

^^-^

^~^^^^~^~-« *

60

*; 8 "~*n

40

O ,- - "O

.- -o

...--•' 0

2U

o-""""'° ^

° o

50

■ o

•

Agtr
Stie,

r
r

= 0.44
= 0.38

^°

40

•

«

c

•

•

V)

^___^^.^^

o

Q.

E

20

■

^

-^

• o

o
<>

10

<3-

-

■ — 0--

f-

O

s

" '^ o

•

0

u. .

#-

-1^-

, ^ , 1

O Cyle. r = 0.60

• Asfoc, r =

-0.36

-

•

•

o

o

♦ o?^

♦ .. --

O.---

■■" o

1 e

-'6' •• •

O 'O

— •♦-• ■

Thickness of B horizon, cm

Fig. 5. ['llk'ct of thickness oi A + 15 liori/on on loiiijiosi-
tioii fh\' foliar c()\er} of grasses, foihs, Ap-opi/roii traclitj-
(■auliiiii. Stipa lettermani, ('yinopteriis leminonii, and Aster
foliaci'iis \. r(inl)iji.

and B horizon (F\^. 5) supported tlu- allrrnatt'
Inpotlu'sis that plant attributes arc uoxeincd
l)\ depth ot soil reniaininti; alter the period of
destructive ff;ra/.in^. it is also appaiciit Iroiii
the differential response of indixidual species
within each ^roup iViil,. 5) that these relation-
ships are not straij2;htf()r\vard.

VVe believe soil and plant attributes that
distinKuish the 6 locations were primarily a
reflection of the jiarent materials and the soil
that remained (niaiiiK li hoii/.on) alter man\
years of destrucli\i' ura/inu and sexcre ero-
sion. F^ilferenccs amonu soils, which in this
case were cIucIIn' a hinction of diirerences in
composition of |xireiit niateiial, were iiiaiii-
fested in soil-xciietation iclalioiiships estab-

lished here. All 6 sites were unprotected dur-
inj4 the period prior to 190.5, and the\- appear
to have suffered more or less equally, losing
50-90% of the A horizon (Kicnnnedson and
Tiedemann 1994). Grazing o\er the past 80 \r
differed among the 6 locations; EK and CP
have been reasonabK well protected since the
1930s. But the impact of differential grazing
since 1905, though marked in the case of EK
and CP locations, appears to be small com-
pared to the differences among sites coupled
with the earlier loss of so nuich of their pro-
ductive capacity through erosion.

COXCLLSIOXS

Although we demonstrated strong relation-
ships among several soil and \egetal proper-
ties, cause-and-effect relationships were not
forthcoming from this information. Compar-
isons with undisturbed areas would perhaps
have pro\ided such linkages. Nonetheless, it
is apparent that \'ield and composition of veg-
etation were closely tied to soil properties. Of
the physical properties, rock co\ er was the
best predictor of \ield and composition of
grasses and forbs. Litter cover was the best
vegetal attribute for predicting forb yield and
composition. Of the soil chemical characteris-
tics, the C,/P( ratio was the best predictor of
forb and grass \'ield and composition.

The opposite response of grasses and forbs
as groups, as indicated b\ regression coeffi-
cients, to all measured attributes suggests that
these 2 groups occupx dillerent serai positions
in successional de\elopment ol this area. Their
roles in successional d>'namics dvv not clearK
defined and will recjuirc" more carehil stud\' of
their responses to soil dexelopment. (Contrast-
ing responses of individual species within
plant groups (Figs. 4, 5) suggest the need to
locus on species-level responses. In a compan-
ion study we are attempting to do this b\'
examining foliar eo\ cm" response to fertilization
with 5 eonibiiiations ol \, I! k. and S lor about
100 species oxer a .5-yr |)eriod.

Depth ol remaining soil, over 90'f B hori-
zon, has not been emphasized in eailier stud-
ies ol this area but Mia\ be an impoitant deter-
Miiiiaiit ill the eoiiipositioii ol grasses and lorbs
as plant groups. Depth ol H horizon \aried
w ideiy among sites and locations and nia\ be a
piimaiN I'eason llial loealioii was sueh an
important laetoi in (lie .iiiaK sis.

1998]

Soil -\i:(;i:rAi Hi:l\tions of Recoverinc; Siumimm: Hwge

361

ACKNOWl.KIXAIKNTS

This researcli was sii|ip()rtccl 1)\ Ciraiits
85-CRSR-2-2717 and 91-38300-6156, Range
Rrsi'arcli Cniut Promain, I SDA-CSRS. The
authors tiratfluIK acknow it-dtfc the Shrub
luipnnenient and RexeUetation Project, Inter-
luountain Research Station, Pro\'o, Utah, for
proNiding facihties lor this research; field assis-
tance of (iar\ Jorgensen, range technician,
Interniountain Research Station, and Dr.
Cl\ (le Blauer, professor. Snow College, both of
Ephraim. Utah; and laboratory analysis by
Justine McNeil, University of Arizona. We
thank Dr. Paul Doescher, Oregon State Uni-
versit), and Dr. Richard E\erett, Pacific North-
west Research Station, for reviews of the man-
uscript. Wt also thank peer reviewers selected
1)\ the Cireat Basin Naturalist for their helpful
suggestions.

LlTER.\TL RE CiTED

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soil development on nutrient c\cling in temperate
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Bowman, R..\. 1988. A rapid method to determine total
phosphorus in soils. Soil Science Society' of America
Journal 52:1301-1304.

Brkmnkr, J.M., AND C.S. Ml LVANEY. 1982. Nitrogen —
total. Pages 59.5-624 in A.L. Page, editor. Methods of
soil analysis, part 2. 2nd edition. .\gronom\ Mono-
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Science Societ\' of America, Madison, WI.

CHAPIN, ES., Ill, .VND G.R. Su.WER. 1985. Individualistic
growth response of tundra plant species to en\ iron-
mental manipulations in the field. Ecolog\' 66:
564-576.

Cole, C.V, and R.D. Heil. 1981. Phosphorus effects on
terrestrial nitrogen c\cling. Ecological Bulletin (Stock-
holm) .33:36,3-374.

Croft, A.R. 1967. Rainstorm debris floods. .Vrizona .\gri-
cultural E.xperiment Station, Tucson. .36 pp.

Di( K. \V..\., AND M.A. Tab.\tabai. 1979. Ion chromato-
graphic determination of sulfate and nitrate in soils.
Soil Science Society- of America Journal 43:899-904.

Dreim.VNIS, a. 1962. Quantitative gasometric determina-
tion of calcite and dolomite b\' using Chittick appa-
ratus. Journal of Sediinentan.- Petrology .32:520-529.

Ellison, L. 1949. Estahlishment of vegetation on depleted
subalpine range as influenced 1)\ nucrocliniate. Eco-
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. 19.54. Sulialpine xegetation o{ the Wasatch Plateau,

Utah. Ecological Monographs 24:89-124.

Hi ENNEKE. L.E, S.R Hamblrc;, R. Koide, II.A. .\1ooney,
AND PM. V'itousek. 1990. Efiects of soil resources
on plant in\asion and communitv' structure in Cali-
fomian serpentine grassland. Ecolog\ 71:478—491.

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Johnson, H.B. 1964. Changes in vegetation of two re-
stricted areas of the Wasatch Plateau, as related to

rcduceti grazing and complete protection. L npul)-
lishcd master s thesis, Brigham ^'oung University;
I'n.vo, UT

Keenev, D.R., AND D.W. Nelson. 1982. Nitrogen — inor-
ganic forms. Pages 64.3-698 in A.L. Page, editor.
Methods of soil anaKsis, part 2. 2nd edition. Agron-
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Klemmedson, J.O., and .'\.R. Tiedemann. 1994. Soil and
vegetation development in an abandoned sheep cor-
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. 1998. Uithosecjuence of soils and associated vege-
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Agricultme, Forest Service, Pacific .Northwest
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362 Great Basin Natl lULisT [Volume 58

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Soil' Science 85:307-318. Accepted 1 7 April 1998

(ireat Basin Naturalist 58(4), © 1998, pp. 363-374

UNDERSTORY PATTERNS IN CUT WESTERN JUNIPER
{JUNIPERUS OCCIDENTALIS SPR OCCIDENTALIS HOOK.) WOODLANDS

jon I). Bales'-, liifliaid I'' MilK'i' \ and loiix Sxcjcai'

Absth\( r. — \\'estc'ni Jiniiiici- i Jiinipcnis orcidciitalis spp. occklentalia) has lapidK cxpaiulcd into sliiiil) steppe eom-
iimnities in the liiteniiouiitaiii Northwest tluriiiy; the past 120 yr. Cutting juniper is a management tool used to restore
slinil) steppe eonimuiiities. Response of the nnderstor\' after cutting is strongl)' influenced by plant species composition
existing prior to treatment. This study assessed distribution patterns of underston' phmts over 2 growing seasons after
tree cutting in a western jimiper woodland. Cover, densit), and diversit\' of underston' species were compared among 3
locations: interspaces, duff zones (pre\i()usl\' under tree canopies), and de])ris zones (beneath cut trees). Plant co\cr and
d(nsit\ increased in all zones following tree cutting. Underston \egetation in cut woodlands exhibited strong zonal dis-
tribution. Cover and densit\' of Poa saiulhcr^ii and Sitanion hijstrix and canopN' cover of annual forbs were greatest in
iluff zones (P < ().()5). Densit\' and cover of other jierennial grasses and total densities of perennial fbrbs and annual
lorbs were greatest in interspaces (P < 0.05). Debris zones tended to ha\e the lowest overall underston- cover and jilant
densit)' values. Under juniper debris many species conunon to interspaces were reduced in density, although plants that
sun ived or established lieneath debris grew larger than tlicir countcrixuts in interspaces. Species that increased in den-
sit\ and cover under debris wfrc plants cliaractcristic of dufi zones and w hose seeds are tvpicalK w ind dispersed.

Key iconl.s: western juniper, nnderslory inillern.s. dirersily. juniper debris, species conipusition, zonal succession.

Pinyon-juniper woodlands in the western
United States have lapidK e.xpanded into
shinh-iiiasslands since the late LSOOs (Tausch
et al. 1981. West 1984, Miller and Wigand
1994). Western juniper {Juniperiis occidentalis
spp. occidcntaUs Hook.) has in\ aded extensive
areas of sauebrush-grasslands and other plant
communities in the Pacific Northwest (Burk-
hardt and Tisdale 1969, Miller and Rose 1995).
The transition ft'om shrub steppe communities
to woodlands has resulted in reduced imder-
stor\ producti\it)' and di\ersity (Johnson 1962,
Jameson, 1967, Burkhardt and Tisdale 1976,
Tausch et al. 1981, Tausch and Tueller 1990,
Bates 1996). Understory distribution patterns
in canopy and interspace zones become more
distinct!)' dexelopcd dmin"; woodland develop-
ment (Johnson 1962, Pieper 1990, Vaitkais and
Eddleman 1991). Understory patterns proba-
bl\- reflect a mosaic of canop\' and interspace
microenx ironineiits. Jiuiipers influence the
microen\ironment under tree canopies b\- mod-
ifying temperatures and light levels (Pieper
1990), accumulating soil nutrients (Docscher

et al. 1987, Bates 1996), intercepting precipi-
tation (Larsen 1993), and causing physical or
allelopathic interference b\' litter lavers (Jame-
son 1966, Peterson and Buss 1974). Padien
and Lajtha (1992) attributed understor\' spatial
patterns in pinyon-juniper woodlands to dif-
ferences in nutrient availabilit\, shade protec-
tion, seed dispersal, and seed germination.

Management prescriptions employed to re-
duce western juniper dominance in rangelands
have been successful in increasing underston'
productivity' and coxer (E\'ans and Young 1984,
Vaitkus and Eddleman 1987, Rose and Eddle-
man 1994, Bates 1996). However, the influence
of spatial distribution on plant succession
following juniper elimination, particularly
with removal methods that leave substantial
amounts of juniper debris on site, are poorK'
doctunented.

Ev aluating understor) distribution patterns
ma\ i^rove useful in generating hypotheses on
species-zonal interactions and in predicting
successional responses and pathwav s follow-
ing juniper control. This stiidv was designed

'Rangeland Resources Department. Oregon State Unixersit), Ea.steni Oregon .Agrieultural Researcli Onter. Bums. OR 97720.

-Present address: Eastern (Oregon .Agricultural Research Center Oregon State l"ni\ers!t>', HC71, Hw\ 20.5. Bums, OR 97720. (The Eastem Oregon Agri-
cultural Research Center is operated jointK- b\' the USD.A-.ARS and the Oregon .-Vgricultural E.\periment Station of Oregon State Universif).)
•'.-Vuthor to whom correspondence should be addressed.
■•USD.X-.Agricultural Research Service, Hwy 205, Bums, OR 97720.

363

364

Great Basin Naturalist

[Volume 58

(1) to assess iinderstor\- distriliution patterns
within an intact western juniper woodland prior
to tree cutting and (2) to evaluate the effects of
tree cutting on understory zonal patterns.

Methods
Study Site

The stud)' was conducted on Steens Moun-
tain in southeastern Oregon, 9.5 km southeast
of Diamond (118°36'W, 42°55'N). Elevation at
the site is 1525 m and aspect is west-facing
with a 22% slope. The site is dominated by an
80-yr-old western juniper woodland. Juniper
canopy cover averaged 23%, and tree density
averaged 228 trees ha~^. The following indi-
cated a fully developed juniper stand: limited
terminal and lateral leader growth on jimiper
trees, lack of juniper seedling recruitment,
and most Artemisia tridentata spp. vaseyana
Nutt. (mountain big sagebrush) were dead.
Understory perennial plant basal cover aver-
aged 2.5% in interspaces and 2.9% under tree
canopies. Based on existing shrub/understoiy
vegetation, soils, and aspect, we judged the
original comnmnity, prior to woodland domi-
nance, to have been Artemisia tridentata spp.
vaseyami/Stipa thurheriami type.

Prior to treatment the dominant understor\'
plant was Poa samlhergii Vasey (Sandberg's
blucgrass), comprising nearly 75% of the total
understory perennial plant basal cover. Other
species characteristic of the site included Stijxi
tliurheriana (Thurber's needlegrass), Sitanion
hystrix (bottlebrush s(|uin-eltail), Agropyron
spicatiim (bluebunch wheatgrass). Astragalus
filipes (basalt milkvetch), Microsteris gracilis
(microsteris), and Alyssmn alyssioidcs (pale
alyssum).

Soils were classified as clayey-skeletal,
montinorillonite, frigid Lithic Agrixerolls. Thc\
arc shallow (40-50 cm deep) and arc underlain
by a thick, welded ash layer of rhyolitc and
rhyodacite comiiosilion, which linu'ts loot
penetration.

Domestic livestock grazing has occurred on
this site since the lale 180()s. Ihc- ridge on
which the study site is located was used as a
sheep wintering area through the 193()s. Since
the 1940s the site has been grazi'd by cattle in
the earl\ sjijring (April). Livestock were
excluded horn the site during our stiuK.

CMimatc in southeastciii Oregon is seniiaiid
and continental. Winter and spring are t\i)i-

call\- cool and wet; simimers are warm and dry.
The majorit>' of annual precipitation falls be-
tween November and June. Mean water year
(1 October-30 September) precipitation at
weather stations located 27 km southwest (ele-
vation 1300 m) and 30 km northwest (1250 m)
of the site average 28.2 and 24.9 cm, respec-
tively.

Experimental Design and
Measurements

In June 1991 we established eight ().8-ha
replicated plots along the contour of the ridge
slope. Plots were selected for similarities in
overstory/understory cover and density, soil
type, and aspect. After being measured for
baseline vegetation characteristics (liasal co\er
and density), juniper trees were felled with
chainsaws in August 1991 on half of each plot
(0.4 ha). Cut trees remained on the plots. We
began subsequent measurements of under-
story characteristics and soil moisture content
in April 1992 and concluded in September
1993. In this paper we report data from the
cut plots only in order to highlight zonal dif-
ferences.

Understory measurements were canopy and
basal cover, density, and diversity. Sampling
was spatially separated into 3 zones: duff,
jimiper debris, and interspace. Duff zones are
defined as those areas formerly beneath tree
canopies with a surface layer of old juniper
needle litter. Debris zones are former inter-
space zones that are covered by felled juniper
trees. Interspace zones are open areas that are
not influenced by old or ncwK felled juniper
tree litter.

We estimated understory plant density
(1991-1993) and canopy cover (1993 only) for
each zone in each replicate, in the 4 cardinal
directions (lor duff and intersi^ace zones onl>),
around 12 trees per replication, using a 30.5 X
()l-cm frame (48 subsamples per zone per
replication). Trees were randoniK' selected
each \t'ar. for the debiis /one wi' I'stimated
densitx and coxer 1)\ landoniK subsampling 4
locations under each of the 12 cut trees in
each replication. We subsampled along the
outer 1/3 ol the duff zone. Interspace zones
weie loeali'd approximati'K 3 m from the
oulei" edgi' ol the dull zone or at the midpoint
bi'twcen dull zones.

Using the eo\cr class teehniciue described b\'
Daubenmire ( 1959), wc eslimati'd canop\ co\er.

1998]

Undehstohy Paitkrns

365

III tliis stiuK 7 (.oxtT classes weiv (lc'sii!;natc'(l:
trace ((>-l%), I (l-.5%), II (.5-25%), HI (2.5->5()'7f ),
I\' (50-75%), V (75-95%), and VI (95-100%).
Midpoints of cover classes were used for sta-
tistical anal\ sis.

I luicrstorx hasal coxcr ot perennial urasses
and lorhs was measured along fi\e 3().5-in line
intciccjits positioned parallel to the slojie in
all S cnt plots in 1991 (baseline \ear, piioi' to
cuttinii), 1992. and 1993. Transects were per-
nianenth marked in 1991 using rebar stakes.
Ciroundcover provided by jimiper del)ris and
old juniper litter in duff locations was also
estimated along the transects.

Gravimetric soil water content was sampled
in interspace and debris zones at 2 depths,
0-20 and 20-40 cm. We collected biweekK
samples on 12 dates during the 1992 growing
season (April-September) and on 13 dates
(lilting the 1993 growing season. In each jilot
5 randoniK located snbsamples were collected
for each zonal depth during each measure-
ment period. Soils were weighed, oven dried
at 106°C for 48 h, and reweighed to determine
percent water content.

Statistical .\nal\ sis

Understor}' data were compared among
zones over time using ANOVA techniques for
a randomized block design. Main effects were
Near and zone. Understory measurements
\\ ere also analyzed each year to help explain
\ ear-by-zone interactions. Snbsamples of under-
stor\' densitv' and canop\ co\er were averaged
by zone per replicate for statistical analysis
in = 8 for each year). Soil water content was
anaK'zed each xear using a repeated-measures
.\NO\'A for a randomized block design. Main
effects were zone and soil depth.

All statistical anaKses were perfoiincd using
the Statistical Analysis System (SAS Institute
1988). Data were tested for normality using
the SAS unixariate procedure. Data not nor-
malK distributed were log transformed to sta-
bilize \ ariance. When interactions were signif-
icant, means were separated using Duncans
new multiple range test. The alpha lexel was
set at P < 0.05 for statistical significance.

Diversity indices were determined for each
zone using densit\' measurements in 1992 and
1993. Hills (1973) Xl and \2 di\ersit> indices
were used as indicators of plant di\'ersit>'. The
N2 index is a measure of ver\' abundant
species and the Nl index is a measure of

cibiiiidaiit species. Hills modified evenness
ratio was used to compare relative abundances
of species among zones (Ludwig and He\nolds
1988).

Results
Climate Conditions and Soil Water

Water year (30 September-l October) pre-
cipitation \alues were 20% below average in
1991 and 1992 at weather stations 27 and 30
km from the site. Study site precipitation in
the 1992 water year totaled 21.3 cm, half of
which was received in June and July 1992. The
1993 growing season was cooler and eastern
Oregon received record amounts of moisture.
Precipitation totals at nearbx' weather stations
were 140% and 149% of long-term a\erages,
respecti\el\. Water \ear precipitation on the
study site totaled 41.8 cm.

In 1992 soil moisture at both depths was
significantK greater (F < 0.05) in debris zones
than in interspaces from late June through
September (Fig. 1). In 1993 soil water at 0-20
cm depth was significantly greater under
debris dian in the interspace (Fig. lA). E.xcept
for 2 periods, mid-May and July, there were
no differences in soil water content at 20-40
cm between the 2 zones in 1993 (Fig. IB).

There were significant time-by-zone-by-
depth interactions for soil water in 1992 and
1993 (P < 0.05). These interactions indicated
that soil water decreased as the growing sea-
son progressed and w as greater at both depths
in the debris zone than in the interspace.
DeiDth-by-zone iP < 0.05) interactions indi-
cate that soil water was greater at 20-40 cm
than 0-20 cm in the soil profile.

Understor\ Densit\ and Co\ er

Pretreatmext vegetation patterns. —
Perennial plant basal coxer in interspace and
duff locations was very low prior to the cutting
treatment (Fig. 2A). Total plant basal cover did
not differ between zones. However, for several
species we detected significant differences in
coxer between zones. Basal co\er o( Poa saiul-
her<!,ii and Sitaiiiun hystrix was greater in duff
zones than in interspaces (P < 0.05, Fig. 2A).
Basal coxer of Stipa ihurJyeriana was highest in
interspaces (P < 0.05). Densities of Poa and
Sitanion were greater in the duff zone than in
interspaces (P <0.05, Fig. 3A). Density' of Stipa,
Agropyron spicatum, and Alyssum allyssioides

366

Great Basin Naturalist

[Volume 58

35

30

i 25

o

(/)

20

15
35

Co^ 30

13
^->
(A

o 25

(A) 0 - 20 cm

nterspace

_ (B) 20 -40 cm

o
CO

20

15

-• — Interspace -
ch- Debris

A M

T"
S

O A

M

1992

1993

Vi^. 1 . \i)luiii(tric soil wiitcr toiitciil in iiil(rs|);icc and dchiis /.ones Ironi (A) 0-20 cm and (B) 20— K) cm dcpllis duiinil
the 1992 and 1993 urowiny seasons. Data aic in means ± v, • Asterisks (*) denote siijiiilieant dillerenees Ixtweeii /ones
{P < 0.05).

wa.s greater in interspaces than in the (ImIT Postthi: vi\ii:\ t \i:(:i"rATi{)N I'.vithhns. —

zone (P < 0.05, Vi^s. 3A, 4A). Densitx' \ allies (love r .iiul deiisitx ol iiiiclerstorN speeies dif-

for annual forhs in 1991 an* prohaMx low and lefed sinniiieanlK anioiiu debris, interspace,

incomplete because sampling; did not lake and diilf /ones (/'< 0.05) alter euttint!; (Piizis.

place until July, well past Hie peak lor aininal 2-1). (."oxer ol perennial plant speeii'S and

(orl) lirowlli. densit\ ol most other nnderstorx speeies

1998]

Um)i:ksi"()ky Paitkrns

367

50
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

- (B)1992

(A) 1991, Precutting

Interspace
Duff

b

a _

n

vm I ll

ni

Posa Stth Pssp Sihy PGT Asfi PFT Total

Debris
Interspace

Duff

ab

b
a a

b a 3

imTy^

1 \ I \ \ \ \ [

Rosa Stth Pssp Sihy PGT Asfi PFT Total

Posa Stth Pssp Sihy PGT Asfi PFT Total

Fiti. 2. Inderston basal cover in (A) 1991 (pii-tuttiiiu; data), (B) 1992, and (C) 1993 for the most common perennial
plants. Different letters denote sisinifieant zonal differences (P < 0.05) between species or plant gronps. Species abbre-
\iations: Posa-Po« s(ind])cr<iii: S\.th-Stipa thiirhcridiia: Ai:,sp-Agropyr(m spicatwii; Sihy-Sitanion hystrix: PGT-perennial
grass total; Brte-Broiim.s tcctonnn: \s{'i-Astra<^(iIii.s filijH's: PPT-peri'iinial lorb total.

368

Great Basin \atltulist

[\blunie 58

c

0)
■D

C

16
14
12
10
8
6

3
2
1

(A) 1991,Precutting

P
Hi

Interspace
Duff

a

i rnl
Stth Agsp Sihy PGT Posa Brte Asfi PPT

w

c
o

■D

c

CL

w

c

0)

■a

c

16
14
12
10
8

4
3
2
1
0

T I \ I r

Stth Agsp Sihy PGT Posa Brte Asfi PPT

(C)1993

bb

ob b, b

a a c b a

a a

5 b

I

4

Debris

Inter.

Duff

b

r-,b

b b

1 r

Stth Agsp Sihy PGT Posa Brte Asfi PFT

I'iK. 3. L'mlciston dcnsitx in (A) 1991 (pnxiittiiiu ilat.u, (B) 1992, and (( I) 199;5 loi llir most coinnion pcKiini.il pi, nils
and ainiual K'assf.s. Dillcicnt icttiTs ck'noti- sij^nilicant zonal dilVcrcnces (/' < 0.05) Ixtwccn species m plan! tiionps.
Species and plant f^roup al)i)re\ iations are delined in Kijinrc 2.

Understoio Pvn"i:i{\s

369

100

80

60

28

24

20

16

12

8

4

0

100 -

(A) 1991, Precutting

Interspace
Duff a

Dl

Alal Depi Eppa Lase Migr Rute OAF AFT

Alal Depi Eppa Lase Migr Rute OAF AFT

Alal Depi Eppa Lase Migr Rute OAF AFT

Fig. 4. Annual torb densih in (A) 1991 (precutting data;, (B) 1992, and (C) 1993. Different letters denote significant
zonal differences (P < 0.05) het^veen species and plant groups. Species abbreviations; Alal-A/(/.s.s!<»i alyssioides;
Depi-Desciirainia pinnata; Eppa-Epilobium paniculatiim: Lase-Lactuca serhola; \\\gr-Micro.steris gracilis;
Rute-Riiiuinculiis tcsticulatus: 0.\F-other annual forbs (e.g., Cirsiuin spp.. Gilia spp.): AFT-annnal forb total.

370

Great Basin NATUii\LisT

[Volume 58

32 h
30
28 -

18 -
b 16 -

> 14 k

O

>, 12

Q.
O

CO

o

8

6

4
2

Debris I I Interspace UTm Duff

b -

a ^b
a „a

a a

'J"

1

i I

b b

a a a

i ft M

J

a a

"1 ^ I I 1 I I \ I 1 \ I r
Stth Agsp Sihy PGT Posa Asfi Croc PFT Brte Aide Migr Lase Depi AF AFT Total

Fig. 5. Posttreatinent canopy cover (%) in 1993 for interspace, duff, and debris zones. Ditterent letters denote signifi-
cant zonal differences (P < 0.05) among species and plant groups. New species abbre\iation: QxoQ-Cvepin occulentalix.
Other species and plant group abbreviations are defined in Figines 2 and 4.

increased significantly between 1991 and 1993
in all zones (P < 0.01). Species that increased
in density {P < 0.05) included Sitanion, Ag,fO}ni-
ron, and most perennial and animal forbs {e\-
ceptAlyssum).

Basal cover of Sitdiiio)!, A.stra^dliis filijx'.s,
Loiuatium dowwlli (Donnells loniatium), and
perennial forbs as a group exhibited signili-
cant year-by-zone interactions (P < 0.05) due
to an increase in basal cover in dull and debris
zones between 1991 and 1993. For most species
there was a lack of year-by-zone interaction
indicating that plant cover and density-domi-
nance patterns remained consistent among
zones between 1991 and 1993. Basal co\er
(Figs. 2B,(:), density (Figs. 3B,(: and 4B,C:),
and canopy cover (Fig. 5) of Fort, SitcuiioiL and
annual forbs remained greatest in duff com-
pared to other zones {P < 0.05). Density and
cover ol other perennial grasses, jMimarih
Af^ropyroii and Stipa, and densit) ol perennial
forbs and Aly.sfiutn were greater in interspaces
than in either duff or debris zones (P < 0.05).

C^anopy cover and deusitx of SiUniion and
canopy cover ol annual lorhs tended to be
greater in debris zones than in intc-rsi)aces (/'
< 0.05). Between 1992 and 1993 basal cover
of peremu'al grasses increased lonrlold in

debris zones. The change in total j^jcrennial
grass co\'er under debris was a result ol in-
creased cover oi Sitanion.

Groundcover also increased by the addition
of juniper debris. Groimdcover pro\ided b\
juniper debris a\eraged 18% in cut plots.
Ibgether with cover provided by interspace
\egetation (18%, see Fig. 5) and 1)\ old juniper
litter in duff zones (22%), total groundcover
after cutting was about 58% in 1993. We
ol)ser\ed that juniper debris was eflectixe in
tiapping sediment washed downslope liom
adjacent uncut woodlands alter hea\\ rain-
storms in July 1992.

PlANT l)l\i:i{sll'Y. — Di\ersit\ and species
ex'enness tendi'd to be greater in the dull zone
in 1991 and 1992 than in the inteispaei' or
debris (1992 only) zones (Table \). In 1993
dixersity and exenness indices in liotli dull
and debris zones were signilieanti\ greater than
in the interspace (/' < 0.05). Higher di\(.'rsit\'
and excnness ratios in dull and debris zoni^s
eonipaicd to the interspace were due to higher
species lielmess ol annual lorbs and lower
densities lA Ali/ssnin and Micro.stcris <j,racili.s.
The high densities ol Ah/s.snin I'educed cxtMi-
ness and dixcisilN in interspace zones. Plant
(li\eisit\ inei'eased belwt'en 1991 and 1993 in

1998]

UNnKHSIOKV PVITKRNS

371

I'viil I 1. I'laiil ili\cisit\ illillsNl and \2j ;uk1 cNrnnrss
ratios in intcT.si)acf, diiH, and di-hris zones. Eveniit'ss
ratios in tliis tabic show a co-dominance of several species
u itii an array of less abundant siiccies.

^ car/ Location

Hills \ I

Hill's N2

E\enness

1911

hilcispace

3.1 a'A^

2.4 iL\

0.5 iL-\

Duff

3.6 aA

2.6 il\

0.5 iiA

1992

interspace

5.1 aB

3.5 aB

0.6 aA

Di.fl"

7.0 bB

4.9 1)B

0.6a.\15

Debris'5

5.2 aB

3.6 dA

0.6iL\B

1993

Interspace

5.9 aB

4.0 aB

0.5 iv\

Dutt"

8.5 be

6.2 be

0.7 1)B

Debris

8.7 be

6.3 bB

0,7 i)B

^Different lowercase letters iiulieate sinnitieaiit zonal tlirtereiiees in ,i year

(P < 0.0.5).

^Different uppercase letters denote significant \<'ar diflerenees \\ ithin a /one

(P < 0.05).

■'Deljris values in 1992 and 1993 are compared to 1991 interspace value because

before cutting in 1991 debris zones were interspace areas.

all 3 zones (F < 0.05). Species evenness in-
creased between 1991 and 1993 in debris and
(luff zones.

There were similarities and differences in
terms of the most abundant species in each
zone. Abundant species in the duff and debris
zones in 1993 wcvv Aly.ssuin, Microsteris, Dcs-
curainia pinnata (pinnate tansymustard), Lac-
tiica serriola (prickK' lettuce), Bromus tectorinn
(cheatgrass), Astra<!,(diis. Poa, and Sitanion.
Abundant species in the interspace were A^ro-
pijwn, Stipa, Poa, Alyssiitn, and Microsteris.

Discussion

Prctrcatincnt Vegetation Patterns

Differences in understoiy composition be-
tween duff and interspace zones indicate that
juniper influences the development of zonal
micrositcs. ('onditions in duff zones were
more favorable for Poa and SiUniioii than asso-
ciated species, whereas conditions in the
interspace favored Stipa and Alyssutn (Figs.
2-5). These plant zonal patterns do not appear
to be related to soil moisture content, as there
were no differences detected in soil moisture
availabilit\ between duff and interspace zones
(Bates 1996). Duff and interspace understoiy
patterns ma\' be related to other factors influ-
encing plant establishment and growth, such
as temperature, light, and nutrient availability.

On warm, suiiu\ days soil teiii|)eratures (5
cm depth) under tree canopies were 4-7°C
lower than in interspaces during the growing
season (1993 data, not shown). Buffering of
temperature e.xtrtMues beneath tree canopies
ma> fa\()r plants that initiate growth relatively
eai'K in the spring, such as Poa and Sitanion.
Cooler temperatures under tree canopies re-
duce evapotranspiration (I hiworth and Mcl^her-
son 1995) and therefore may decrease under-
stor\' water stress.

We did not measure pholosynthetic active
radiation (PAR) in this stucK; but there wt-re
indications that light levels for plant growth
w^ere reduced under canopies in duff zones in
1991. In 1991 we observed that perennial
grasses tended to exhibit etiolated growth
patterns in duff zones under tree canopies.
Several studies have reported that as light lev-
els decrease beneath the tree canopy with
pinyon-juniper woodland development, peren-
nial grass co\'er decreases (Schott and Pieper
1985, Pieper 1990). Therefore, lower light lev-
els in duff zones than in interspaces may be
responsible for lower cover and density of
perennial grasses. The combination of reduced
light levels and lower temperatures also reduces
seed germination of annual plants (Baskin and
Baskin 1985), which may explain why annual
plant densities were lower in duff zones \'er-
sus the interspace.

Posttreatment Vegetation Patterns

There were significant increases in under-
storx' co\er densit\, and di\ersity after juniper
cutting. These increases occurred mainly dur-
ing the 1993 growing season, which was char-
acterized by more fa\'orable growing condi-
tions (higher spring moisture). Plant response
to the cutting was limited in 1992 due to diy
conditions occurring from late winter through
the spring. However, the abilit) of the under-
stoi) in the cut treatment to respond in the
high precipitation year was made possible b>'
eliminating juniper competition for soil mois-
ture and N (Bates 1996). We believe the under-
storx' response in the cut treatment resulted
from elimination of juniper competition Ijecause
in adjacent uncut woodland the understory
showed little response to increased precipita-
tion in 1993 (Bates 1996).

Zonal underston plant composition did not
change in duff or interspace zones after cut-
ting. Species with greater cover (Figs. 2, 5) or

372

Great Basin Naturalist

[Volume 58

dcnsit}' (Figs. 3, 4) in duff zones, such as Poa
and Sitanion, rcMiiaincd dominant in the duff
zone while Stipa, A^ropyron, and Alyssum
remained dominant in the interspaces. These
results suggest that early postcutting under-
stoiy composition, particularly for zonal domi-
nants, is predictable based on pretreatment
understory floristics. Predicting understory
d\ namics after cutting, however, proxides only
a (|ualitative estimate. Predicting a quantita-
tive response is more difficult due to a num-
ber of uncertainties, particularly postcutting
weather conditions. Uncertainty is also intro-
duced b\' lack of knowledge about the quan-
tity and composition of soil seed bank resen'es
(Koniak and Everett 1982) and the level of
understory seed production following release
from juniper competition. For instance, the
increase in plant diversity and species rich-
ness (Table 1) in our study appears to have
largely resulted from the emergence of plants
from soil seed banks and belowground bulbs
and tubers. Understory succession following
pinyon-juniper removal by fire is also guided
by initial site floristics, although prediction of
posttreatment response is again limited to
(qualitative estimates (Everett and Ward 1984).

After cutting, plant cover increased more
than did density, especialK for perennial plants,
because existing perennial plants grew larger
in size. Between 1991 and 1993 total perennial
grass l)asal cover increased by nearly 200%,
but perennial grass densities increased by onl\'
65% in duff zones and 43% in interspaces. The
lower density response of perennial grasses
was due to the lack of seed production. Except
lor Sitanion, little seed production in the
pcremiial component was obser\('d in 1991 or
in 1992. In 1993 we observed that perennial
grasses allocated a large poition of their
growth to reproduction, rlie higher peri'imial
seed crop in 1993 ma\ alter plant composition
on the site in subseciuent years.

Uitter layers in duff zones continued to in-
IliKiice species establishment and growth lol-
iowing cutting. Plant densit\ and coxcr were
greatest in the outer portion ol the dull /one,
decreasing with |)r().\iniil\ lo tlic lice stump
where litter depth was greatest (Bales 199(i).
In other pinyon-juniper woodlands, plant den-
sil\ and cover decreased as the tree bole was
approached and litter la\ers thickened (I'.xcrelt
and Sharrow 1985, Dye et al. 1995). Juniper
litter max inteileic with seed genninalion and

seedling establishment by phx'sicallx' impeding
seed-soil contact, reducing soil temperatures,
and restricting plant growth via allelopathy
(Jameson 1966, Peterson and Buss 1974).
Although allelopathic effects should not be
discounted, they seem unlikely given groxvth
patterns of plants established in duff areas.
Plants that were established or became estab-
lished in the dufT zone tended to groxv larger
than their counterparts in the interspace, par-
ticularly annual grasses and forbs.

There was a propensity for greater estab-
lishment of Sitanion and sexeral annual forbs
[Lactuca, Cirsium spp. [thistles]) in duff zones
than in interspaces. This may be a product of
seed dispersal and catchment mechanisms.
Seeds of Sitanion and these annual forb species
are typicallx xxind dispersed. We hxpothesized
that old juniper needle litter in duff zones is
more eflPective in trapping wind-dispersed seeds
than the relatively bare soil sm-faces character-
izing the interspaces.

Juniper debris had negative and positixe
effects on understory plants. Prior to cutting
in 1991 debris zones xvere interspaces. After
trees were cut and debris zones created, com-
position of the understoiy shifted, dexeloping
greater similarity to duff zones than to inter-
space zones. In both years folloxx ing juniper
cutting, cover and density of Sitanion and the
folloxving wind-disseminated annual forbs
increased under juniper debris: Lactuca, Epi-
Johinni paninilatian (xvilloxv-xveed), and Cir-
sium spp. These plants tended to establish
along the outer edges and less heavilx' shaded
or open patches of the debris zone. These re-
sults indicate that microenvironmental changes
can alter species composition and successional
pathxxax's.

The increase in Sita)iion densitx under
(k'bris suggests that debris also max be benefi-
cial lor establishment ol other grass seedlings.
Once needles fall from the debris and suffi-
cient perennial grass seed sources are axail-
able, junipei' debris max serxf as imjiortant
niicrosiles lor other perennial grass seedlings.

Total annual lorb densitx and coxi-r and
densitx of pciciuiial gi'asses (except Sitanion
and l\)a) and perennial lorbs xx'ere still signifi-
cantlx loxxcr under debris than in interspaces
(/' < 0.05) in 1992 and 1993. Negatixc effects
ol juniper debris on perennial grasses (except
Sil(ntion and Poa) and loibs xxcre particularly
exidenl in 1992 x\heii lonipared lo intersjiace

1998]

UNDERSToin Patikhns

373

\ allies ill 1991. Perennial liiassos, such as SlijXL
and lorbs (e.g., Aslr(i<:,(iliis) were killed niuler
hea\\ debris accumulations as e\idenced l)\
their reduced densities.

The neiiatixe impact of jiniiper debris on
amiual lorbs, partieuhirK Alyssuiii and Micros-
teris, may have resulted from lowered seed
geniiination and/or plant establishment. Dimin-
ished light le\'els and lower soil temperatures
due to shading by juniper debris may reduce
seed geriniiiation and establishment of aiiiiual
forl)s, thus resulting in decreased forb density.
Ihmexer, annuals and perennials that did estab-
lish in debris were generalK larger and sta\ed
acti\e longer into the season than their coun-
terparts in the interspaces (Bates 1996).

The larger indix idual sizes of plants and
their prolonged growing season under debris
max haxe been a product ol improxed plant-
xxater relations. Higher soil moisture levels
(Fig. 1) under debris are hx'pothesized to have
resulted from a combination of reduced evap-
oratixe loss and loxver moisture demand by
plants. Reduced temperatures and increased
boundary layers provided by pinyon-juniper
debris loxxer xapor pressure gradients, therebx'
reducing transpirational demand (Gifford and
Shaxv 1973). The loxver densitx of plants under
debris also may have resulted in more avail-
able resources per plant than in the inter-
space, thus contributing to larger plant size.

Results from this studx support findings
from ()tlu>r pinxon-juniper systems that under-
ston plant composition is influenced bx' zonal
location. There has been little discussion about
the effects on understory zonal patterns of
juniper remoxal by cutting, fire, or other means.
Our studx' determined that while there xvere
significant increases in plant coxer and densitx
resulting from juniper remoxal, there xvas little
change in relative species (understory zonal
dominates) composition in duff or interspace
zones. Predicting (jualitatixe species composi-
tion in duff and interspace zones, at least in
the first 2 x r postcutting, is possible from pre-
treatment conmiunitx' Horistics. Understory re-
sponse to the deposition of juniper debris is
less predictable. Changes to the microenx iron-
ment caused by juniper debris rapidly shifted
understorx' plant composition. How juniper
debris affects xegetation dxnamics ox'er a longer
period of time is cnrrentlx- being monitored on
this site. We hxpothesize that overall plant
connnunitx composition and development xx ill

not be radically altered bx juniper debris since
debris coxcrage axerages only 18% across the
site.

ArKXOWI.KDCNH^XTS

W'c thank l'>ed Otlex and familx for use of
their propertx during the studx. Thanks to
Kara Paintner and Jeff Rose for statistical help
and assistance in the field. Thanks are due
to Lee Eddleman, Dave Ganskopp, Wendy
Waichler, and 3 anonxnious reviewers for their
comments and suggestions. This manuscript
xx'as submitted as Technical Paper 11,161 for
the Oregon Agricultural Experiment Station.

LrrER.\TUHE Cited

1I\SK1\. J.M.. AND C.C. Baskin. 1985. The annual domiancy
cxclc ill buried weed seeds: a continuum. Biosciencc
.35:492^98.

B.ATES, J.D. 1996. Underston vegetation response and
nitrogen cycling rollovving cutting of western juniper.
Unpublished dissertation, Oregon State Universitx,
Corxallis. 230 pp.

BURKHARDT, J.W., AND E.W. TiSDALE. 1969. Nature and
successional status of western juniper vegetation in
Idaho. Journal of Range Management 22:264—270.

. 1976. Causes of juniper inx'asion in southxvest

Idaho. Ecologx' 57:472-484.

Dalbenmire, R.E 1959. A canopy-coverage method of
vegetational analxsis. Northwest Science 33:43-64.

DoESCHER, PS., L.E. Eddleman, and M.S. V'aitkus.
1987. Evaluation of soil nutrients, pH, and organic
matter in rangelands dominated by western juniper.
Northwest Science 61:97-102.

DvE, K.L., D.N. Ueckert, and S.G. Whise.nant. 1995.
Redbern- juniper-herbaceous understory interac-
tions. Journal of Range Management 48:100-107.

E\A\s. R.A., AND J.A. YoiNG. 1984. Plant succession in
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ExERETT, R.L., AND S.I I. SnARROW. 1985. Underston- re-
sponse to tree harvesting of singleleaf pinxon and
Utah juniper. Northwest Science 45:10.5-112.

E\ ERElT, R.L., AND K.O. VVakd. 1984. Earix' plant succes-
sion in pinyon-juniper controlled bums. Northxvest
Science .58:57-68.

Cii'i'ORD. G.E, AND C.B. Sh.\\\. 1973. Soil moisture patterns
on two chained pinxon-juniper sites in Utah. Journal
of Range Manageiiient 26:43(i-44().

H,\\\()RTH, K., AND G.R. McPherson. 1995. Effects of
Quercus eonijri trees on precipitation distribution and
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Hii.L. M.O. 1973. Diversity and evenness: a unifying nota-
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Javieson, D.A. 1966. Pinvon-juniper litter reduces growth
of l)lue grama. Journal of Range Management 19:
214-217.

. 1967. The relationship of tree overstory and herba-
ceous understorx' vegetation. Journal of Range Man-
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374

Great Basin Natl iulist

[\blume 58

Johnson, T.N. 1962. One-seedt'd jimipfr iina.sioii of north-
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187-207.

KoMAK, S., .WD R.L. EvEHETT. 1982. Seed resene.s in soils
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Mli.i.EH, R.E, .\ND PE. \\'iG.\ND. 1994. Holocene changes
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PlEPER, R.D. 1990. 0\erstory-understory relations in
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SciioiT, M.R., AND R.D. PlEPER. 1985. Influence of canopy
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Talscii, R.J., AND PT. Tleller. 1990. Foliage bioniass
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Received 1 1 June 1997
Accepted 21 January 199S

Cifal Basin Natmalist 58(4), © 1998, pp. 37.>-;379

COMPAKATIN E DEMOClUFllY OF nil-: llICll-ALllTLDE LIZAKD,

SCELOPORUS GRMIMICUS (PHRYNOSOMATIDAE), ON THE

IZTACCIHUATL VOLCANO, PUEBLA, MEXICO

Julio A. Lemos-Espinal', l^cnce E. Ballinger^, and CTeottii'\ H. Smith ^

Abstr.\c:t. — Population dciisitN. rcprociiictiou, and .sui\i\()r.sliip were coiiiparccl bi'luccii 2 populations ol Sceloporm
firammicus occurring at diflerent altitudes (3700 m and 4400 m) on the eastern slopes of Iztaccihuati Volcano, Puehla,
Mexico. Lizards in hoth populations matured at the same age (14-15 mon) and size (39-42 mm SLV). Population densit>
was slightK greater at high altitude ! 1)1 -163 per ha) than at low altitude (52-83 per ha). Survivorship and R„ were
higher at the low-altitude area, hut in general there were no significant demographic variations between altitudes that
ha\ e been reported in lizard population at higher latitudes. Studies of lower-elevation populations might re\cal some
dillerences because pre\ious studies indicate that litter size increases at lower altitudes, altliougli tlii'\ do not differ
between our 3700 m and 4400 m I'jopulations.

Key word^: lizard lijc history, dcmo^iraphy. reproduction, (dtitude variation. Seelopoms granunicus, })opulation den-
sity, replacement rate, survivorship.

Liff histories and demographic traits of
hzards can \ar\ along elevational gradients
(Ballinger 1979, Grant and Dunham 1990,
Smith and Ballinger 1994a, 1994b). Altitudinal
\ariations in life histor\ characteristics often
mimic \ ariation obser\ed across broader geo-
graphic ranges that can be attributed to differ-
ences in en\ironnienta] conditions (e.g., Adolpli
and Porter 1993. 1996). In addition, some stud-
ies have shown that altitudinal \ariation can
ha\'e at least a partial genetic basis (Smith et
al. 1994, Ballinger et al. 1996), just as studies
on geograjihic \ariation ha\e shown (Ferguson
and Talent 1993, Xiewiarowski and Roosen-
burg 1993). Most of these studies have focused
on lizard populations in north temperate lati-
tudes. Understanding how life histories and
demograplu' vary in response to latitude and
altitude comliinations may be useful in identi-
f\ing \ ariables responsible for such changes.

In this paper we present data on (Umuo-
graphic \ariation of 2 populations of Seelo-
poms granunicus Wiegmann, 1828 at different
elevations (3700 m and 4400 m) to examine
whether \ariations in demograplu occur at
subtropical latitudes. Sccloporus grammiciis is
a small, \i\iparous lizard that occurs from

southern Texas, USA, to the state of Oaxaca,
Mexico (Conant and Collins 1991, Flores Vil-
lela and Gerez 1994). This species has been
poorly studied and little has been published
on its biologx, except for studies on its repro-
duction (Guillette and Casas-Andreu 1980,
1981, Ortega and Barbault 1984), general pop-
ulation biologx' (Lemos-Espinal and Ama\'a-
Elias 1986), growth (Lemos-Espinal and
Ballinger 1995a), and thermal biolog\' (Lemos-
Espinal and Ballinger 1995b).

Materials and Methods

The 2 populations we studied are located in
the Campo Experimental Forestal San Juan
Tetla (19°1()'N', 98°36'\\') on the eastern slope
of Iztaccihuati Volcano, Puebla, Mexico, at
3700 and 4400 m. On Iztaccihuati \blcano, S.
granunicus can be found up to 4600 m eleva-
tion. At this latitude tree line is 4()()() m. The
l()w-ele\ation site (herciiftcr designated Laguna),
of approximate!)' 4 ha, is located in a Pimis
hartwcgii forest surrounding a natural lake.
Lizards were seen primariK on logs and
stumps but were occasionally found under
tree bark or in cracks in tree trunks. This site

'Proyecto Fauna Silvestre, CENID-COMEF/SARH, .\venida Progreso #o. Viveros de Coyoacan, Mexico, D.E (MUO.
-School of Biological Sciences. Unix ersity of Nebraska-Lincoln, Lincoln, NE 68588. Correspondence author.
^Department of Biolog>, WiUiam Jewell College, Libert\. MO 6406S.

376

Cheat Basin Natuiulist

[\bluiiie 58

M '^

O) 3

Laguna

Paredon

y =

- 5.300 + 0.194X R = 0.85 y^

DBnnn y^

y^'

DEO Myfcmii

/

/ QO D

1 ■ 1 ■ 1

30 40 50 60

Snout-Vent Length (mm)

30 40 50 60

Snout-Vent Length (mm)

Fig. 1. Relation.ship of litter size to body size in pregnant Sceloporu.s graininicu.s from low- (Lagunaj and high- (Pare-
don) altitude populations on the Iztaccihuatl Volcano, Puebla, Mexico.

was studied from November 1984 to June
1988, and from September 1990 to January
1992. The high-elevation site (hereafter desig-
nated Paredon), of approximately 1 ha, is a vol-
canie roek formation surrounded by grassland
composed primarily of Festiica tolucensis.
Lizards at this site live under rocks and in rock
crevices. We studied this site from Noxember
1985 to June 1988, and from September 1990
to January 1992. From May 1991 to April 1992,
average minimum temperatures for these 2
sites were veiy similar (Laguna = 2.0 ± 0.6°C
[mean ± 1a-],' Paredon = 2.2 ± 0.6°C); how-
ever, average maximum temperatures for
Laguna were higher (13.1 ± 0.9°C) than for
Paredon (5.7 ± 0.5°C; Lemos-Espinal and
liallingcr 1995a).

Both populations were censused monthl).
For each captured lizard we measured snout-
vent length (SVL) to the nearest mm using a
clear plastic ruler, and body mass (BM) to the
nearest 0.01 g using a Pesola'" spring scale.
We also recorded sex, tail condition (broken,
regenerated, or unbroken), time of capture,
and microhabitat of cai:)ture site. Each lizard
was pennaiK'utK marked by toe clipping, 'lb
examine reproduction, we collected lemales in
adjacent areas more than 500 in from the 2
study sites (n = 67 for Laguna, n = 54 for
Paredon) during May 1991 and dissected tlieiii
to examine reproductixe tracts (speciiueiis
cinrently in JALs personal collection). Size and
number of volked follicles or embrvos were

recorded for each female. All means are gi\en
± \sj, unless specified othenvise.

Using Jolh's (1965) stochastic method, which
is relatively insensitive to ditlerences in chance
of captin-e or sui"vival among animals (Carodiers
1973), we calculated population density for
each month. Although \'oung and old lizards
ma\ haxe differed in capture freciuencx' and
survivorship, bias in population estimates was
probably small (Smith 1981).

Lizards were aged according to size at first
capture. Since Lemos-Espinal and Ballinger
(1995a) found that lizards from both stucK'
sites show the same growth rates, we used the
same size categories for both populations: size
class 1 (females <39 nun S\'L, males <42 nun
SVL; iudixiduals in their 1st yr), size class 2
(females 39-45 mm SVL, males 42-49 nun
SVL; indi\'iduals in their 2nd yr), and size class
3 (females >45 nun SVL, malt>s >49 mm
SVL; 3 \'r or older). For lite table aiuiKses we
estimated age by recaptiui- ol animals marked
as hatchlings or by using \ on Bertalanffy ^957)
growth analyses (Lemos-Espinal and Ballinger
1995a). Sur\ i\ orship was estimated for each
age class as the proportion ol marketl animals
reeapluicd the h)ll()\\ iiig \ear.

KksL LIS

Litter si/i- inirea.sed with leniale body si/e
in both populations (Fig. I ; /" = ().S5, // = (i7,
P < ().()()() 1 lor Laguna, and r = 0.S9, n = 54,

1998]

Di'.NKx.KAi'in oi'^ S(i:iA)ronrs crammicus

377

F < ().()()() I for Paicdoii). lu'inalcs Iroiii Laij;ima
had siiiiiilicantlx lartifi" litter si/x-s than did
feiiuik's from Faivdon, after eontrolliiiu for dif-
ferences in body size with ANCOVA (3.64 ±
0. 10 [n = 54] vs. 3.31 ± 0. 13 [n = 67]; Fj j , 7 =
4.92, P < 0.03). The interaction term was not
siunificaiit. There was no indication in our
stiid\, or in that of CTuillette and Casas-Aiuhcu
(1980), that females have more than 1 litti-r
per \ear.

Lizards at both stud\ sites were born at
19-20 mm SVL. Females attained sizes of
approximate!)' 39 mm SVL by 14 mon of age
(Lemos-Espinal and Ballinger 1995a). The
smallest reprodncti\e female was 39 nnn SVL
at both Laguna and Paredon, but an SVL of
appro.ximateK' 40-42 mm was the typical min-
imum size of reproductive females (Fig 1).
These data indicate that females at both study
sites mature at an age of 14-15 mon (i.e., in
their 2nd k\\).

Annual sur\'i\'orship (1^) was calculated for
1985-86 and 1986-87 at Laguna, and for
1986-87 at Paredon. In general, survivorship
tended to be greater at Laguna than at Pare-
don (Fig. 2). The number of indi\iduals per ha
was greater at Paredon than at Laguna for all
years of study (Table 1).

Contriliution of the different age classes to
age-specific fertilit\- was similar at both study
sites. Age classes 2 and 3 contributed the most
(32% and 29% at Laguna, and 30% and 31% at
Paredon; see Table 2). A\ erage generation time
was 3.32 \r for Laguna and 3.37 yr for Pare-
don. Replacement rates varied between years
as did average population density (Table 2).
Lower R^, \alues in 1987 may ha\'e resulted
because both stud\^ sites were sampled onK 6
mon in 1988 (until June 1988); thus some
lizards that survived from 1987 to 1988 ma\
not have been registered.

Discussion

In general, the 2 populations of S. gramini-
cus studied here do not differ greatK' in their
biology. Survivorship estimates appear to be
slightly higher in the Laguna population, but
the difference is quite small. Growth rates and
body temperatures also do not differ between
these populations (Lemos-Espinal and Ballinger
1995a, 1995b). One of the few population dif-
ferences is litter size. Females from Laguna, the

1e+0

o

>

3
(0

5e-1

•*•■ 85 • Laguna

-♦• 86 - Laguna

•*■ 87 - Laguna

-^ 86 • Paredon

-•- 87 - Paredon

0 12 3 4 5

Age (years)

Fig. 2. Siirvixoisliip (I^) cur\es for Sccloporus ^ra)nini-
cti.s from low- (Laguna) and high- (Paredon) altitude popu-
lations on the Iztaccihuatl Volcano, Puebla, Mexico.

l()w-ele\ation site, had siightK larger litters
than did individuals from Paredon, the high-
elevation site. This difference may help
explain the difference in R^ between these
populations: Laguna's R^ suggests a growing
population, whereas Paredon's suggests a
decreasing population. It is interesting to note
that litter sizes of S. grammicus from lower-
elexation populations (2000-3200 m) are e\en
larger (mean = 5.2) than from our Laguna site
(Guillette and Casas-Andreu 1980).

The lack of major differences between these
2 populations of S. grammicus is in contrast to
sexeral other studies of elevational variation in
life histor}' and demographic traits, such as
growth (Grant and Dimham 1990, Smith and
Ballinger 1994a) and siu"\i\()rship (Smith and
Ballinger 1994bj. While it is tempting to attrib-
ute differences between the present study and
other studies to geography (i.e., differences in
latitude) or elevation (present study took place
at higher elevations than other studies), such a
conclusion is premature. Our results, taken
along with those of (Guillette and Casas-Andreu
(1980), do suggest there may be additional ele-
\ ational differences among populations of S.
grammicus if a broader range of elevations
were studied. Our results also suggest that
further studies comparing populations at dif-
ferent elevations from a variety of latitudes
would be useful in elucidating potential causes
of life history and demographic variation in
lizards (and other ectotherms).

378

Great Basin Naturalist

[Volume 58

Table 1. Average population densitv' for 2 populations oi Sceloparus uraininicus Iroiii tlif I/tacciliuatI NolL-aiio. Puchla.
Mexico for 5 v n Densities are given as indivichials per hectare.

Population

1985

1986

1987

1988

1991

Laguna
Paredon

81

79
153

83
16.3

52
131

1.35

T.'\BLE 2. Age-specific tcrtilit\ rates (l^ni^j and K,,s lor low- (Laguna) and high- (Paredon) altitude pojiulations oi Scclo-
ponis ^raiiimicii.s from the Iztaccihuatl \blcano, Puebla, Me.xico. Absolute longex it\ is unknown, i)ut 5-\r-old animals ha\e
been recorded. Life table was arbitrarii\ stopped at the end of the 6th \r.

Laguna

Age

1985

1986

1987

Mean

0

0

0

0

0

1

0

0

0

0

2

0.423

0.439

0.273

0.378

3

0.375

0.398

0.243

0.338

4

0.239

0.259

0.154

0.217

5

0.152

0.169

0.099

0.140

6

0.095

0.107

0.062

0.089

Paredon

1986

1987

\U'an

0

0

0

0

0

0

0.207

0.181

0.244

0.334

0.170

0.252

0.223

0.98

0.160

0.148

0.056

0.102

0.096

0.0.30

0.063

1.284

0.831

59

1.108

0..5.35

0.821

Acknowledgments

For field as.si.stanee and use of laeilities, we
thank Ql. Praxedis-Martinez and woikers from
the C^ampo Experimental Forestal San Juan
Tetla. Financial .support to J.L.-E. was pro-
\'ided by the Institute) Nacional de Investiga-
ciones Forestales y Agropecuarias and the
Consejo Nacional de Ciencia y Tecnologia.
J.L.-E. is especially grateful to Ing. C. Gonza-
les Vicente and S. Sanoja Sarabia foi' advice
and support.

LiTEH.vri'Ris Citi:d

Adolph, S.C, AM) W'.P i'oHTKH. 1993. Temperature, activ-
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. 1996. (irowlh, scasonalilv, and li/.iid illc liislories:

age and size at maturity. Oikos 77:267-278.

BalLINCKH, H.E. 1979. Jntraspecilic variation in demogra-
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Ballinckh, H.E., (;.i^ Ssinii, and J.W. Nii.n i.i.dt. 199(i.
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CaHOTIIKHS, A.D. 1973. The elTecIs of une(|ual calcliabilily
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Ferguson, G.VV., and L.G. Talent. 1993. Life-histor\ traits
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Flores Villel.\, O., and R Gerez. 1994. Biodiversidad y
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Gr\NT, B.W., and A.E. Dl NllAM. 1990. Elevational eman-
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GriLLEiTE, L.j., \\n (;. C.vsas-Andrki. 1980. Fall repro-
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. 1981. Seasonal variation in fat bod\ wi'ights oi

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generates sobri' la ecologia poblacional de la lagar-
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1 998]

Dkmochm'iiy oi Sf 7 /.()/'( )«rs chammicvs

379

. 1995b. Comparative tluTinal (.xoloiix ol tlic liiuli-

altitiide lizard ScclopDru.s ^raminicti.\ on tin- t-astcni
slope of tlif IztaccilniatI \blcaiio, PiR'hla, Mexico.
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NlKWIAKOWSKl, PH., AND VV.M. RocsENBURG. 1993. Reti-
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Received 11 June 1997
Accepted 20 January 1998

Great Basin Naturalist 58(4), © 1998, pp. 380-385

NEW BISEXUAL FORM OF CAVERNOCYPRIS SUBTERRANEA
(WOLF 1920) (CRUSTACEA, OSTRACODA) FROM IDAHO

Okan Kiilkoyliioglu' and Gar\' L. Viiiyard'

Abstract. — Males of Cavemocypris siibterranea were found for the first time in an Idaho spring. The bise.xual form is
described based on soft body parts and valves. The genus Cavernocypris now includes 2 bise.xual and 1 parthenogenetic
species.

Key icords: Cypridopsinac, Cavem()c\pris subterranea, crcnohiont. Inseximl fonn, ecology, Idaho.

A recent re\ision of the genus Cavemocijpris
Hartmann (Ostracoda, Cypridopsinae) by Mar-
monier et al. (1989) suggested that this genus
contains 3 species: Cavemocypris suJ)terranea
(Wolf 1920), C. coreana (McKenzie 1972), and
C. wardi Marmonier, Meisch, and Danielopol,
1989. Of these, only C. coreana and its sub-
species C. coreana elongata in South Korea
have been reported to e.xist in bise.xual popula-
tions (McKenzie 1972, Marmonier et al. 1989).
Parthenogenetic populations of C. subterranea
are known from Europe and central Asia, and
parthenogenetic C. wardi has been reported
from the western United States (Marmonier et
al. 1989, Forester 1991, Ward et al. 1994). An
undescribed species, Cavemocypris, n. sp., has
also been reported from Arizona (Danielopol
et al. 1994).

This stu(l\' presents the first report of the
bisexual form of Caveniocyj)ris subterranea
and provides the first description of males of
the species.

Mvniiu ALs AND Mkihods

We collected 25 iudixiduals (8 males and 17
females) on 4 August 1993 from Head Spring,
near Brush Creek, in Malad City, Snake Valley,
Bannock County (TUS, R38E,'Sec 7), Idaho.
Specimens were collected using a hand diji-
net with a mesh size approximatcK 1 nmi-,
preserved in 10% formalin, and snbs((|U(iitl\
stored in 70% ethanol. After isolating ostracods
from the samples, we dissected specimens and
nionnfcd thcni in lactoplicnol. Species identi-

fication is based both on soft body parts and
valves. Ecological and physical data collected
from the collection site are shown in Table 1.
All materials have been retained in the Depart-
ment of Biology, University' of Nevada, Reno,
except for 7 specimens deposited at the Musee
National d'Histoire Naturelle, Lu.xembourg,
b>' Dr Claude Meisch.

Description

In general, modern ostracods are described
based on their soft bod\ parts and valves.
Detailed information about the terminology
and more description of the parts can be found
in Moore (1961) and Wm Morkhoven (1962).

Malk. — Shell, viewed dorsalK', is elongate
and the width less than half the length. There
is no double-folded inner list on the posterior
margin of the left vaKe (LV), and L\' (range,
0.67-0.73 nun) is slightly longer than the right
valve (H\'; range, 0.63-0.73 mm). Height (H) is
less than half the length (L; range. 0.2(-)-0.34
mm) and approximately etjual to the width {W:
range, 0.27-0.33 nun). In lateral view (Figs. lA,
1 B), \ aKc's are elongate and LA' oxerlaps R\'
both auteriorK and posteriorly. The posterior
end is slightU' narrower than the anterior, but
both are roimded in dorsal \ic-\\. The lusi'd
zone of the inner lamella is wider at the ends
and broader anteroxcntralK. \'al\c's ai'c whitish-
opacjue and sniootli. In souu' i'.nropt'an speci-
mens the \ aKc'S nia\ liaxc a dorsa-median
band with pits. Some indixiduals ma\ lack
this band ((,". Meisch, jjiixembonrg, personal

'l)<p;irliiH-iil of iiioloKy' #311. I'loKiairi in KioloKy. l'Aiil>ilii)ii. aiul CoiiMiTalinii HioIdhv li

lU'iH), NV S95r,7-(M)15.

380

1998]

NFA\ BiSKXl AI. C.\VF.R\()CYPHIS SiBTFJUlWEA

381

TaHIK 1. Kt()l()<lic;il and pliysical data ci)IIfitc(l
stiidx site.

.NaiiK'

Head Spring, Malad (.'it\.

and location

Snake \'alle\. Bainioek C'onntx.
ldaho;TllS, R38E, SecT

Latitnck'

42°48'43" N

Lonuitndc

112°06'09"W

Eli'\ation

1842 m

Water teuiper

iture

9.6°C

C()n(huti\it\

528 |iS/ciii

pH

7.73

coiMinuiiicatioiij. In our siK'cinu'ii.s ck'calcifica-
tion luLS clcstroNX'cl this pitted area if it was
present.

The 1st antenna (Fig. IC) or anteiumla (al)
has 7 segments (joints) with long natatory
setae (as in females). Numbers of setae on
each segment of al are 3:1:1-2:3:4-5:4:4.
Unhke females, there is no row of delicate
setae on the 1st segment of al of male speci-
mens. The rome organ (r) is poorK' de\ eloped.

The 2nd antenna (ti2) is 4-segmented (Fig.
ID). Swimming setae of a2 on the 2nd seg-
ment are reduced to 6 small setae, 5 of which

= 5Qam

Fig. 1. Cavernocypris sitbterranea: A, left \al\e of male (inner view); B, right valve of female (inner view); C, 1st
antenna (antennula) (al): D, last 3 joints of 2nd antenna (a2) (2nd joint bears 5 short and 1 longer setae); E, mandibula; K
mandibular palp; G, rakelike organ with 7 teeth.

382

Great Basin Natuiulist

[\'olunie 58

Fij^. 2. Cmcrnocypris suhtcrranea: A, maxillae of male formed as rij^ht prehensile palp and left (V>) prehensile palp; ("
maxillae of female in normal shape; D, maxilhila and m;ixilhilar palp of male; E, Zenker organ w itii 1 1 w hoils; V. hemipe-
nis (lateral shield |ls| is spatula shaped): (i, turea of lemali'.

I)arcly extend to the proximal margin ot the
penultimate joint or podomore (3rd segment).
The 1st dorsalK loeated natatorx seta extends
hallway up the penultimate joint (as in females).
All sensory clubs "aesthetasc" (Y, Vj, y2, ya) are
present. The aesthetasc Y is 1 -segmented and
its length ecjual to 33% of the dorsal edge of
the 2nd segment and 37% of tlie xentral edge
ol the 2nd segment. 'Hie t and z setae are
reduced on the 3rd segment. (]lavvs i.\ and
C2 are about e(|ual in length, 2/3 longer than
(i3 and 5/12 longer than the 2nd segment,
('laws are serrate, [.eugth of the (JM claw on
the 4th segment is about e(|ual to 03 and 38%
longer than the claw (\\\\ thai is about llic
same size as oi- sHghlK longer than \ ;.

The mandibula (h'ig. 1 1''.) I'uds with (i tcclli
and 3 small sclac, 1 liair\ and 2 snioolh. Thcic

are also 2 other setae, kl and k.2. fhe position
ot kl is between the 1st and 2nd teeth, and k2
is between the 2ud and 3rd.

The mandibular [Xilp (Mdp) is 4-si'gnu'nted
with a i-espiialoi\ plate (Fig. I !•'). The (X, [3,
and Y setae are pii'seut on the 1st, 2ud, and
3rd seguK'uts, respeeti\ cK. llic Isl si-gment
also carries 1 long seta and SI si'ta. but the S2
seta is reduced or absent. The (3 seta on the
2n(l segment and the y seta on (lie 'ird scg-
UKMit are leather) w hilc the (X seta is small and
smooth. There are also 2 small and 2 long
setae on the 2nd scgnicnl. which reach almost
lo the tips ol the claw s. The .'^rd segment has 2
grou|)s olsctiie, S (olal. In (lie 1st (dorsal) group
are 2 small and 2 mi'dium setae, whereas tlu-
2nd (\cntial) group has 4 setae, all similar in
sizi'. The 4th seiimeni has 2 ilaws and 2 setae.

1998]

\i w Bisi \r\i. CwiiiMxiriiis si ivrrmiwiA

383

= 50jum

Fig. 3. C(ncnwcii])ri.s suhtcrninca (male): A, Ist thoracopod (Tl); B, 2nd thoracopod (T2).

The maxilla (Max) is formed as left and right
prehensile palps with 10-12 medium-sized
apical setae placed on the opposite end ot the
endopodite. Right prehensile palp (Fig. 2A) is
slightly larger than left (Fig. 2B). The subter-
minal segment of the left palp has 2 small,
claw like setae (1 on the right palp). Two feathen'
branchial filaments are seen on the exopodite
plate, a diagnostic character of the species.
Two small setae (2a) are also seen on the oppo-
site side.

The maxillula (Maxl) (Fig. 2D) bears 3 mas-
ticatory processes and 1 ma.xilhilar palp (the
4th joint). The terminal segment of the palp is
rectangular in outline with .5— (i setae, 1 of which
is alwa\s small. The length of the 2nd segment
of the palp is twice its width. The outer (3rd)
masticatory process of the maxillula has 2
spinelike setae and is scarceh' toothed.

The 1st thoracopod (Tl, walking leg) has a
long, faintl>- toothed distal claw (Fig. 3A), its
length nearly equal that of all 4 segments. The
distal seta of the penultimate segment is long
and well de\eloped. In addition to the distal
claw, the 4th segment bears 1 small seta.

The 2nd thoracopod (T2) with 4 segments
is ended with 1 pincer organ, 1 well-dexeloped

seta (or 2 small setae), and 1 beaklike claw
(Fig. 3B). No serrate setae occur.

A flagellum-like furca is absent in males but
present in females. A small hook-shaped seta
is located on the proximal part of the furca.
The rake-shaped organ (Fig. IG) is T-shaped
and has 7 teeth.

The Zenker organ has 11 spinous whorls
(Fig. 2E), and 1 specimen of 3 shows 3 Zenker
organs rathei- than 2. The hemipenis (Fig. 2F)
is of cypridopsine type and subtriangular in
shape. The base of the lateral shield (Is) of the
peniferum is straight, the medial shield
rounded.

FkmaI-F.. — Shape and surface structure of
the vaKes are as in males (Fig. IB). Mean
length and width of the shell of 12 females were
smaller than that of males: L = 0.67-0.69 mm,
1 \ = 0.20-0.30 mm, W = 0.20-0.26 mm. A row
of delicate setae is found on the 1st segment of
al. The 3rd segment has 2 setae (1 is reduced
in males). Claws Gl, G2, and G3 on a2 are
sulxHjual. The maxilla is shaped normalK and
not formed into palps (Fig. 2C). Flagellum-like
furca is present (Fig. 2G). Other appendages
are similar to those reported b\' Marmonier et
al. (1989).

384

Great Basin Natur.\list

[\blume 58

Table 2. Comparison ot inali's ot the species C. rorciina and (.'. suhterrunea.

Character

C. coreana

C. subterrama

Size

al

C3 claw

t and z setae

Aesthetasc Y

Maxilla

Zenker organ

Lateral shield
Flahitat

0.66 mm (eUmgata)

().72mm {coreana)

6-segment

short seta

present

long, 2-segment

with 4 filaments

6-8 whorls ielongata)

8-9 or 12 (coreana)

duck-head shaped

ca\'e waters

0.70 mm

7-seginent
normal

reduced/absent
1-segment
2 filaments
11 whorls

spatula shaped

cold springs, rivers, caves, mountain lakes

= 200jum

c ,.~

B,C,D ^

= 50jum

Fig. 4. Cavemocypris coreana elongata (male): A, right \alve; li, right prehensile palp; C. left iirehi-nsilc palp; D. right
hemipenis, iiuier view (from Marmonier et al. 1989 with permission ot Dv. Claude Meisch).

DlSC;USSK)N

Detcnniiiatioii ol .sexual diiuoiplii.sm in
Cavemocypris subterranea i.s based on tlic
occurrence of reproductive or^an.s and liuca,
size of the shell, shape oi the nia.xilla, and dif-
ferences in the length ol claws ((il, C2, G3).
The description of females ol C. siihtcnanca
by Marmonier et al. (1989) also included
descriptions of 2 additional species. Of these,
C. coreana is bisexual. The males of these 2
species (Table 2) can be com|iared as follows:
(1) C. coreana (Vi^. 4A) is smaller than (.'. .s7</^-

tcrrafiea; (2) a! is 7-sejj;mentt'd in ( '. sithti'r-
rancd, hut (i-segmented in ('. coreana; (3) the
(;.■> elaw on the antenna is reduced to a tin\',
short se(a in ( '. corcdiuL I>ut (.'.] is iioiuial and
claw like in ( '. subterranea. The t and /, setae
are ri'dnced in (.'. subterranea while C. core-
ana has 2 t and 2 /. si'tae; (4) C. subterranea
has 2 branchial filaments on the exopodite
plate of the maxilla, but C. coreana has 4
branchial lilanu-nls (Im.^. 41i, 4C); (5) the lat-
eral shield of the hcmii^enis {V\%. 4D) is duck-
head shajK'd in C coreana but spatiilate
shaped in (.'. subternniea: ((i) Zenker oruan 1 I

1998]

New BisKxiAi. C.wi.Rxocyrnis slbteriiwea

385

whorU'd ill ('. suUtcninwa, hut 8-9 wlioiis in
C. corcana corcana, and 6-8 in C coreana
cloiiLidtd. which can also hear 12 whorls (Mar-
inoiiic r ct al. 1989). Although 1 of our speci-
iiR'iis had 3 Zenker oiuans, this is considered
ahenant and is not used for comparison oi these
2 species. However, this characteristic may he
important if the condition is found to he com-
mon. \h)rphol()tiical and anatomical anomalies
of some freshwater ostracods (C>. Meisch per-
sonal communication) were reported from
Sweden and Poland after the (;hern()l)\l acci-
dent (B. Scharf, German), personal communi-
cation), hut the presence of 3 Zenker organs
was not ohser\ed. Further studies are needed
to assess causal factors for this anomaly. Hahi-
tats of these 2 species are different. C. coreana
is known onK" from the cold limestone cave
waters in Korea, while C .suhtcrraiwa is creno-
biont and occupies a wider range of environ-
ments including cold spring waters, river and
alluvial bed sediments, caves, and the littoral
zone of mountain lakes (Xhinnonier et al. 1989).
Based on these differences, we propose
that the bisexual form of C. subterranea is con-
generic with the bisexual forms of C. coreana,
but not conspecific. They constitute 2 distinct
species.

Conclusions

Twent\'-fi\e (8 males and 17 females) indi-
viduals of the species Cavernocypri.s subter-
ranea were examined. The bisexual form of C.
subterranea was found in a cold water spring
in Idaho and is described for the first time.
Description of the males is based on valves,
soft hod) parts, and comparison with the other
known bisexual form, C. coreana. Differences
of morphological characters, structures, and
ecological parameters indicate that males of C.
subterranea are different from males of C.
coreana, but the same as parthenogenetic
females of C. subterranea found in Europe.

AcKXow i,i;i)(;\iF.NTS

We thank Dr. CJlaude Meisch (Miisee
National d llisloiri' Naturelle, Luxembourg)
for his help, comments, and encouragement as
we prepared this stud\. Thanks are also given
to Dr Dinger C^iilen and his colleagues at the
University of Istanbul (Turkey) for their com-
ments and assistance obtaining the camera
Incida, to Dr Burkhard SeharfO^epartment of
Inland Water Research, (ierman\) for per-
sonal communication, and to Robert Schroeter
(University of Nevada-Reno, USA) for his
re\iew of an early draft of this manuscript.

References

Damelopol, D.L., R Marmomkr, A.J. Boulton, and G.
BONADUCE. 1994. World .siil)tenanean ostracod hio-
geograpli)': dispersal or xicariancf. Ihdrohiologia
287:119-129.

Forester, R.M. 1991. Ostracode assemblages from springs
in the western United States: implications for paleo-
hydrolog\'. Memoirs of the Flntoniological S()ciet\- of
Canada 1.5.5:181-201.

Marmonier, R, C. Meisch, and D.L. Damelopol. 1989.
A review of the genus Cavernocypris Hartmann
(Ostracoda, Cypridopsinae): systematics, ecology and
biogeograph\. Bulletin, Societe Naturelle de Lu.xem-
bourg 89:221-278.

McKenzie, K.G. 1972. Results of the speleological suney
in South Korea 1966. XXII. Subterranean Ostracoda
from Soudi Korea. Bulletin, National Science Museum
(Tokyo) 15:1.55-166.

Moore, R.C. 1961. Treatise on invertebrate paleontology.
Rart Q. Arthropoda 3, Crustacea: Ostracoda. Uni\'er-
sit\' of Kansas Rress, Lawrence. 442 pp.

Van Morkhoven, ERC.M. 1962. Post-Ralaeozoic Ostra-
coda. Volume I. Their morph()log\, ta.xonomy and
economic use. Elsevier Publishing Conipan\\ New
York. 204 pp.

Ward, J.V., J.A. Stanford, and J.N. N'oelz. 1994. Spatial
distribution patterns of Crustacea in the tloodplain
aquifer of an alhnial rixcr. H\clrobiologia 287:11-17.

Received 30 September 1997
Accepted 6 January 1998

Great Basin Naturalist 58(4). © 1998, pp. 38(i-389

AN UNDESCRIBED ASrRAGAL(7S (LEGUMINOSAE) FROM SOUTHERN

UTAH, A NEW SUBSECTION OF THE GENUS, AND VALIDATION OF

THE COMBINATION SPHAERALCEA JANEAE (WELSH) WELSH

Stanley L. Welsh 1

Abstract. — ^One new species. Astragalus concordius Welsh, sp. nov., is deserihed from Wasliintitoii and IrtJii counties,
Utah, and section Argoj)lnjIIi. subsection Concordi Welsh, subsect. nov., is proposed. A complete bibliographic citation is
supplied to validate the nomenclatural combination Sphaeralceajaneae (Welsh) Welsh, Memoirs Great Basin Naturalist 9;
423. 1987.

Key words: faxonoiny. Astragalus, new specie

s, noiiieiic

hit I

While I was preparing keys to the species
o{ Astragalus for the Flora North America pro-
ject, my attention was drawn again to some
peculiar plants from the Pine Valley and Koloh
portions of Washington County and adjacent
Iron Count)', Utah. Because of the peculiar leaf
pubescence contrasting sharply with that of
the pod, the plants will not ke\' to any species
known for Utah or Nevada in either of the
previous treatments by Bameby (1964, 1989) or
Welsh et al. (19S7, 1993). The plants superfi-
cially resemble A. piutcnsis Barneby ik Mab-
i^erley (A. uiariamis Rydberg) of section Argo-
phylli, subsection ArgopJujIli, and most have
been identified as such. The main similarity,
apart from luibit, in\'()lvcs the long-hairy pods.
However, the plants in question are appressed
strigose with definitely malpighian or dolabri-
form pu])esccnce, a feature not known from
subsection Argophylli but typical of subsection
Missourienses. Only A. atnphioxys of subsec-
tion Missotiriensc's occurs within the range of
the plants in question, and that plant has
merely strigose pods. Barnebx (1964:697) states:

The subsect. Missourienses is iieatK circumscribed
and delined by the iirescncc ol dolabrilorm hairs,
bill il would !)(■ lia/.ardous to assume thai il is a
truly natural nionoph) k'lic group. On IIr' contrary,
it seems possible that the species have arisen inde-
pendently, either singly or in pairs, from alreacK'
existing ArdoplujUi with basifi.xed vesturi- or irom
precursors ol these at some remote period in the
past.

Barneby (1964) then indicates examples of
potential species pairs between those with
basifixed and those with malpighian pubes-
cence. Possibly this is the situation between A.
piutensis and the new proposal. The species is,
nevertheless, anomalous in any of the previ-
ously proposed subsections of section Argo-
phijlU.

Section ArgophylJi A. Cra>-

Subsection Concordi Welsh,
subsection nov

Similis sectione Argoplujlli subsectioiie
Argophylli in legiunini i^ubescenti sed aliter
dilferet et similis subsectione Missourienses in
pilis dolabriformis sed in legumini pubescenti
differt.

Typk ,SPEC:ies. — Astnigdlu.s coficordius Welsh,
sp. nov

Subsection ('oncordi is clearly allied to sec--
tion Argophylli, subseclion Argophylli. with
which it shares caudex features, sliagg\, long-
hair\ pods, and general habit, but differs in
the malpighian pubescence ol tlii' heibage. It
shares the feature ol herbage pubescence with
iiicnibers ol subsection Missourii')}ses, but not
the pod pubescence.

This proposed new species li.is huig passed
inider A. piuliiisis lianiebx (S; Mabbciley.
.VltJioiigli placed in a different subsi'cliou of
Argophylli because ol contrasting pubescence
t\pes, it appeals lo be mosl cIoseK allied to. A.

'M.I.. Bean l.ilc Snciiic Mmmmmii .iiiti I )i'|>.u linciil ol H»laii>. lirmli.uii Vanm I iiiMiMh. I'ni^.i. l'TS.m()2

386

1998]

New Southern Utah As//; vcvv/.rs

387

piiili'ii.sis. \'\\c l()uu-li;iii\ [)()(ls ol .A. con-
cordius are not shaird 1)\ other species of sub-
section Missouriensi's hiil are known in some
species in subsection Ncwhern/dni. In that
subsection the most similar species, so lar as
pod pul)escencc is concerned, is the strict!)
acaulescent (not subacaulescent) A. wclshii
Barneby. which has only incipientK malpi<j;hian
hairs on the herbage and chtfei's in other
regards. Welshes' milk\etch, an endemic of
south central I'tali fniaiuK on igneous gi"a\ -

els), is disjuiicl by uiau\ kilometers Irom the
present proposal, \\ith the nearest approach in
th(» Black Mountain vicinity in northeastern
iron (.'ounty. Kelationship of subsection Con-
cordi to subsection Xcichi'm/dni appears to be
tenuous.

A.stragtdii.'i concordiiis W'elsh, sp. nov.

(Fig. 1)

.Si nulls Astragalo piuiensi (sectione Ar^io-
pliijlli. subsectione Ar<i.()i)hylli) in aspectem

i^;

HOLOTTr-OF

Uc^L. .^C^XH-C^yLMUA-. kJ&^

Fig. 1. Photograph of't\pe specimen oL\stra<:(ilu.s concordiu.s Welsh.

388

Great Basin Naturalist

[\blunie 58

generalem, seel pul)escentis clolaliriforinis (nee
basifixis) foliolis saepe rotundatis \v\ apieulatis
et ealyee tantuni strigulosis differt.

Perennial, subaeauleseent, 9-15 em tall, fiom
a branehing caudex. Pubescence nialpighian.
Stems 0-6 cm long, the internodes mostly
concealed b\' stipules, these 3.5-9 mm long,
all distinct. Leaves 3-9 mm long; leaflets
11-17, 3.5-13 mm long, 1.2-5 mm broad, obo-
\ate to oblanceolate or elliptic, rounded to
apiculate or acute, appressed strigose on both
sides. Peduncles 1-10 cm long; racemes 2- to
8-flowered, the flowers ascending at an thesis,
the axis 0.5-5 cm long in fiuit; bracts 2.5—4.5
mm long; pedicels 1.5-2.5 mm long; bracte-
oles 0. Calyx 10.5-12 mm long, the tube
8.5-9.5 nun long, cylindric, strigulose, the
teeth 2-3 mm long, subulate. Flowers 21-25
mm long, pink-piuple or whitish to lilac-
tinged. Pods spreading-ascending, sessile or
nearly so, the body 15-40 mm long, 9-13 mm
thick, ovoid to lance-acuminate, obcom-
pressed, almost straight to incurved, densely
shaggy-hirsute, unilocular. Ovules ca 30.

Type.— USA: Utah: Iron Co.: Flat Top Mt,
ca 6 mi NE New Harmony, T37S, R12W, S31,
6200 ft elevation, 24 May 1976, S. Welsh, K.
Taylor, and F Feabody 13160a, holotype BRY
(4 isotypes distributed previously as A. tnari-
anus Rydb.).

Other c;()llecti()ns (paratopes, all BRY).
—USA: Utah: Iron Co.: Spring Creek, SE
Kanarraville, 16 May 1985, D. Atwood 11003;
do, W Grants Ranch, T37S, R14W, S27, 30
May 1986, R.B. Warrick 1672; do. Upper
Grants Ranch, T37S, R14W, S36, 3 June 1986,
R.B. Warrick 1762. Washington Co.: along
Santa Clara River, T41S, R17W S17, 22 April
1961, A. Tcrril s.n.; do, E slope Pine Valley
Mts, T39S, R13W, S19, 8 June 1981, D.
Atwood 7901; do, 5 mi SW Enterprise Rcsim-
voir, T38S, R19W, SI, 10 June 1981, D.
Atwood 9362a; do, S Kolob Reservoir, T39S,
HIIW: S27, S June 1983, F.C. Iliggins & A. II.
Barnum 13606; do, I-: slope Pine \'alle> Mts,
T39S, R13W, 16 Max 1984, D. Atwood 9652;
do, Pine Spring Wash, T39S, RllW, S34. 23
April 1984, B. Franklin ik C. Baird 462; do,
Kolob Terrace, T39S, RllW, S34, 7 June 1948,
S.L. Welsh, L. Iliggins, & K. Thorne 22941:
do. Pine Valley Mts, Main ( aiiNon, I3SS,
R14W, S33, 2 June 1986, R.B. Warrick 1715;
do. Fine Valley Mts, T38S, R13W, S9. 17 Mav
1986, R.B. Warrick 1379; do. Piiic Spring

z
m

<
>

>

\ r 1

X IRON

/ Ceda

City

It

GARFIELD

"■ ' !• X

*7^

washingj<5n

• (S) ^-^

St George^/"^

KANE

^^O-" ARIZONA 1

Astragalus concordius welsh

Fig. 2. Map of southwestern UtaJi showing distrihiitioii
oi Astragalus concordius Welsh in Washington and Iron
counties.

Wash, T39S, RllW, S34, 28 May 1986, L.C.
Higgins 16741; do. Horse Ranch Mt, T38S,
R12W, S24, 9 Julv 1987, K. Thorne & S. Clark
5368; do, Kolob Plateau, T38S, RllW, S2&34,
2 Julv 1988, G.I. Baird 3021; do. North Creek,
T40S, RinV, S34, 3 May 1988, K.H. Thorne &
M.A. Franklin 6014; do, Kolob vicinity, T40S,
RllW, S12, 29 April 1989, S.L. Welsh & S.L.
Clark 24162; do. Hop Valley, T39S, R12W,
S12, 23 May 1989, L.C. Higgins 18372.

Flowering occurs mainly dining April and
early May; hence most specimens are in fruit.
The species occurs with ponderosa pine, man-
zanita, oak, aspen, mixed mountain brush,
pinyon-junipen and less coinmoiiK with l-Ve-
mont poplar, willow, and ash, or rarclx with
creosote bush, at (1200) 1340-2600 m, uiaiuK
on sandstone or soils deri\ed from sandstone.

Anomalous in an\ of the currentK known
subsections of .V/i,'* )/)/)/////. ,V. coiicordiu.s is most
similar \('getati\ t'l\, except lor its malpighian
hairs, with A. piiitcnsis. from which it dilfi'rs
also in se\eral less tangible featmes; i.e.,
leaflets are coinmonK rounded to apiculate,
not obtuse to einaiginate oi' aenniinate; cal\ \
is merely stiigulose, not pilosulons; and at
least some pods are nuieh longer

Distribution ol the species (Fig. 2) centers
in the llarmonx Mountains, Iron Count), L'tah,
and I'ine \alle\ Mountains and Kolob Plateau
legions ol Washington County. The area oceu-
|)ie(I l)\ most known collections is an o\al
a|ipm\iinal(l\ 10 km long and 20 km wide.

1998]

\i;\\ SoriiiKKN U lAii .A.s//,',\(;.A/,( s

389

trciulinu; aloiii:; a iiortliw cst-soiitlR'ast axis.
OiiK' 2 collections arc known to he remote
from the main bocK of the species, one alont!;
the Santa (-lara Kixcr, ca 10 km west of the
town 1)\ that name, and the other from the
Bull \alle\ \h)nntains southwest oi Enter-
prise Heser\()ir. The Piute milkxctch is mainK
a plant oi the southeastern (ireat Basin with
onK a slitiht o\('rla[) oi distribution in the Pine
\'alle\ Mountains.

Ol the numerous specimens initialK con-
sidered to be A. piutensis, onl\ one is from \\\v
Pine \'alle\ Mountains; the remainder are
honi other L tah and .\e\ada localities. Thus,
the 2 species are e\identl\ di.sjunct, though
contiguous, as are other closcK related species
elsewhere in the genus.

A matter unrelated to the new species of
Astragalus was called to my attention by Dr.
K.N. Gandhi, Gray Herbarium card index bib-
liographer, concerning the lack of proper for-
mat in what turned out to be an incomplete
citation (a lapsus calamus) oi SpJiacralcca janeae

(WV'lsh) Welsh, published without citation of
bibliographic reference of the basionx ni. The
hill citation should read, "Spliacndci'd Janeae
(Welsh) Welsh, Memoirs, (ireat Basin Natural-
ist 9: 423. 19S7. [basionxni; Spliacralcca Icpto-
plu/lla \di: janeae Welsh, (Jreat Basin Natural-
ist 40: 27. 198()J." This information merely val-
idates the earlier, intentional combination.

LriKHATURE ClTKI)

B AHNKBY, R.C;. 1964. .\tla.s of North American Astragalm.

Memoirs of" the New York Botanieal Garden 13:

1-1 1S8.
. 1989. Falwles. Pages 1-279 in A, Crontinist. A4I.

Holmgren, N.H. Holmgren, J.L. Reveal, and i^K.

Holmgren, Intermouiitain Flora 30:1-279.
Welsh, S.L., N.D. Atwood, S. Goodrich, \\d L.C. Hig-

GINS. 1987. A Utah flora, (ircat Basin Naturalist

Memoirs 94-894.
. 1993. A Utah flora. 2nd edition re\ised. .Monte L.

Bean Life Science Museum, Provo, UT. 986 pp.

Received 21 November 1997
Accepted 17 February 1998

C;reat Basin Naturalist 58(4), © 199S. pp. 390-392

AGE AND GROWTH OF JUNE SUCKER
{CHASMISTES LIORUS) FROM OTOLITHS

MarkC. Belk'
Key words: June sucker. Chasmistes liorus, fl^p, <ir<nifli. life Iiisfon/. lUoIitlis. I'taJi Lake.

June sucker, Chasmistes Jionis, is endemic
to Utah Lake, Utah County, Utah (Miller and
Smith 1981). This species is federally listed as
endangered, and the wild population may
number <5()0 individuals (based on mark-
recapture estimates, C. Keleher, Utah Dixision
of Wildlife Resources, personal communica-
tion). The remaining C. liorus population
appears to suffer from lack of recruitment to
the adult population, apparently in part due to
predation on juveniles by an abundant popula-
tion of introduced white bass {Morone chnjsops;
U.S. Fish and Wildlife Serxice 1995). Present
recovery' efforts include artificial propagation.
Adult C. liorus are captured as they proceed
up the Provo River to spawn, gametes are
stripped and combined, and offspring are
raised in captivity until they reach a size large
enough to axoid predation b\' white bass. These
juveniles then are returned to Utah Lake,
except for those retained as brood stock. To
cffecti\'el\' evaluate siu-\'ival of captive-reared
inch'\ iduals and to estimate age at recruitment
to the breeding population, one nnist under-
stand natural patterns of C. liorus growth in
Utah Lake. Although adult size is well docu-
mented, no data are available on C. liorus
growth patterns. In this paper 1 report growth
pattern, size at age, and age at death of indi-
\iduals estimated from presumptive annuli on
otoliths (lapilli) from 10 C. liorus from the wild
liopulation. This study provides previously
iuia\ailal)le data on age and growth to serve as
a baseline lor comparing (.. liorus growth pat-
terns.

Ten ('. liorus (7 in June 1992 and 3 in June
1994) died from unknown causes, possibK as a
result ol stress associated with s|xiwniiig acti\-
ities, and weri' recoNcrcd 1)\ the I tali l)i\i-

sion of Wildlife Resources. Standard length,
total length, mass, and sex were recorded for
each individual. Lapilli were removed, cleaned,
and embedded in epox\' resin (Serifix, Struers
Corporation, Westlake, OH) for sectioning.
Otoliths were sectioned in the frontal plane
using a lapidaiy grinder (Struers Model DAP-
7, Struers Corporation, Westlake, OH) and
mounted on a glass slide. Thin sections were
observed with a Wild dissecting microscope at
24X to determine number of annuli (age), and
images were captured via a video camera
mounted on the microscope and a TARGA
board in the computer to measme annual
increments on otoliths. Annual increments for
the first 10 presumptive annuli were mea-
sured with the use of MOCHA image anaKsis
software (Jandel Scientific Inc.). Estimated
length at age was calculated using the follow-
ing fornuila (modified Fraser-Lee method,
Campana 1990):

L, = /.„ + (L,. - L„)(fl, - R„)/(R,. - R„)

where L^ is estimati>d total length at age .v, L^.
is length at capture, R^ is otolith radius at age
A", and R^. is otolith radius at captiuv. L,, is esti-
mated length at swim-uj) (1 I nun; Sinder and
Muth 198(S), and K„ is estimated otolith radius
at swim-up (0.09 nun, measured from otoliths).
An age-growth curxi" foi- ages 1-10 was gener-
ated by averaging back-calculated si/.i>s at age
for each sex (Fig. 1).

I'Atiniated agi's ol indixidnals ranged iioin
10 to II \v. Two in(li\ iduals had 10 presuinp-
ti\c annuli a! dcalli in 1^)^)2. All otlicrs had
more than 25 aiuuili at dc-alh (Table 1). Chiis-
niistcs liorus exhibited a 3-stagi' growth jiat-
tern. Baek-taK'ulated lengths at age indicated

' Ofparlmeiil of Z<xjlogy. BriKiiaiii Voiiiik L'liivcrslly. I'lovo. I T H-K)()2.

390

1998]

Notes

391

Tahi.k 1. Presunipti\e age, sex, total length, year of death, and estinuitcd total length at pic-siimptive ages 1-10 lor 10
('hasinistcs lioni.s. Total lengths at ages > 10 \r were not calculated.

I'rcsiMiiptixc

Estimated total length at annnlus

agi'

Sex

TL

IXath

1

2

3

4

5

6

7

S

9

10

10

M

502

1992

87

256

355

421

461

477

492

498

501

502

10

1"

52fi

1992

101

277

388

437

468

487

503

520

522

526

■26

M

518

1992

91

259

343

380

393

414

430

449

469

470

31

jr

580

1992

197

294

353

397

425

457

476

497

517

538

34

539

1992

149

273

302

332

351

366

390

421

434

457

35

5(iS

1992

70

176

232

262

299

330

348

368

382

403

41

555

1992

141

204

264

320

365

395

420

438

451

455

30

55S

1994

7S

203

296

325

366

383

393

411

421

430

36

592

1994

97

205

251

291

327

348

373

394

405

424

37

M

502

1994

9(i

172

214

255

286

322

350

369

380

400

544

31.7

232
45

300
59

342
64

374
63

398
6(J

418

437
54

449
53

460
49

500

9 10

Fig. 1. Mean (±ls^) total length at age 1-10 for male (n
= 3) and female (n = 7) C. lioriis in Utah Lake, Utah Co.,
Utah, USA. Length at age calculated from presumed
annual increments on otoliths. Length at ages >10 was
not calculated.

rapid growth for the first 3-5 \ r, and indi\ icki-
als averaged 69% of mean total length at death
b\' the 5th presumptive annulus. Following
this rapid growth, individuals exhibited inter-
mediate growth rates until about age 8-10.
Eight\-five pereent of mean total length at
death was achieved b>' the lOth annulus (Table
1). Growth after age 10 was further reduced.
Growth trajectories did not appear to differ
between se.xes within the first 10 \r, and esti-
mated length at age 10 did not differ between
sexes (F > 0.1, Wilcoxon rank sum test, SAS
1990; Fig. 1). Based on condition of gonads
and presence in the spawning aggregation in
Pro\"o Ri\er, all indixiduals were reproduc-
ti\el\- mature at time of death.

Although 10 is a relati\el\' sniiill sample size,
this sample may represent 2% of the remain-
ing population, well above the proportion sam-
pled in most studies on age and growth offish.
Because C. liorus is endangered and indi\ idu-
als cannot be obtained easily, validation of
ages derixed from otoliths has not been done.
Validation of age estimates using otolith annuli
has been done for other c>'prinids (leatherside
chub [Gila copei\ Johnson et al. 1995; Utah
chub [Gila atraria], unpublished data), and C.
lioni.s appears to exhibit similar patterns of
annulus formation. Ages deri\ed from sec-
tioned otoliths of Xyraiichen texanus have
been validated for younger age classes, and
ages appeared reliable for older age classes
(McCarth\ and Vlinckley 1987). However,
until a \ alidation studx' of ages derixed from
sectioned otoliths of C. liorus is possible, ages
in this study should be considered preliminarx'
(Beamish and McRulane 1983).

In most fishes growth rate decreases after
sexual maturit)- (Aim 1959). Chasini.stes liorus
examined in this study show a decreased rate
of growth after about 5 annuli, and all individ-
uals in this stud\ were reproductixcK mature.
Assiuning that decreased growth rate indicates
probable maturation, C. liorus ma\' mature as
early as age 5, but at least by age 10. In 1980
the smallest reproductixe indixiduals xx'ere
440 and 490 mm total length for males and
females, respectixely (Shirley 1983). If groxx'th
patterns of these fish are similar to that docu-
mented in this study, then the smallest indi-
xiduals likelx' xvould have been 6-10 vr old.

U.S. Fisii and Wildlife Serxice (1995)
reported total length of reproducing females

392

Grkat Basin NATurL\LiST

[Volume 58

was larger than males in both 1980 and 1991.
Until age 10 growth patterns do not differ
between sexes in this study. However, all
females were larger than males, suggesting
that differences in total length between sexes
result from increased growth of females rela-
tive to males after sexual maturation.

C. liorus age and growth patterns appear
similar to those of other large-bodied western
suckers (e.g., Chasmistes cujiis, Scoppettone
1988, Scoppettone and Vinyard 1991; Xyrau-
chen texanm, McCarth\' and Minckley 1987).
Delayed matinity and long adult life may be
adaptations to uncertain recruitment caused
by environmental fluctuations (Scoppettone
and Vinxard 1991). These characteristics have
allowed populations of C. lionis and other sim-
ilar species to persist, even though recruit-
ment has been extremely limited because of
recent human disturbance. It is my hope that
recovery' efforts can improve recniitment before
the aging adult population becomes extinct.

I thank C. Keleher and the Utah Division
of Wildlife Resources, and U.S. Fish and
Wildlife Service, for help in obtaining C.
liorus otoliths. M. Lambert prepared and sec-
tioned the otoliths. D. Shiozawa, C. Keleher,
G. Scoppetone, and H. Tyus provided reviews
and valuable suggestions for improvement of
this note.

Literature Cited

Alm, G. 1959. Connection between niatnrity, .size, and age
ill fishes. Institute of Freshwater Research, Drott-
ninghohn 4():.5-145.

Beamish, R.J., and G.A. McFari,a\e. I9S3. The foriiottcn
refjiiircMieiil for age vahdatioii in fisheries liiology.

Transactions of the Ainerican Fisheries .Societ\ 112:
735-743.

Campana, S.E. 1990. How reliable are growth back-calcu-
lations based on otoliths? Canadian Journal of Fish-
eries and Atjuatic Sciences 47:2219-2227.

Johnson, J.B., M.C. Bki.k, and D.K. Shiozawa. 1995. Age,
growth, and reproduction eif leatherside chub {Gila
copei). Great Basin Naturalist .55:183-187.

.McCarthy, M.S., and W.L. Minckley. 1987. Age estima-
tion for razorback sucker (Pisces: Catastomidae) from
Lake Mohave, Arizona and Nevada. Journal of the
Arizona-Nevada Academy of Science 21:87-97.

Miller, R.R., and G.R. Smith. 1981. Distribution and
evolution of Chasmistes (Pisces: Catostomidae) in
western North America. Paper 696. Occasional Papers
of the Museum of Zoolog>-, Uni\ersit> of Michigan,
Ann Arbor. 46 pp.

SAS. 1990. SAS user's guide: statistics, \ersion 6 edition.
SAS Institute, Inc., Can; NC.

Scoppettone, G.G. 1988. Growth and longevit\ of tlie
cui-ui and longevity of other catostomids and
cyprinids in western North America. Transactions of
the American Fisheries Society 117:.301-.307.

Scoppettone, G.G., and G. Vinyard. 1991. Life histoiy
and management of four endangered lacustrine
suckers. Pages 359-377 in W.L. Minckley and J.E.
Deacon, editors. Battle against extinction: nati\e fish
management in the American West. University of
Arizona Press, Tucson.

Shirley, D.L. 1983. Spawning ecolog\ and lar\al de\elop-
ment of the June sucker. Proceedings of the Bon-
neville Chapter, American Fisheries Societ\ 1983:
18-36.

Snyder, D.E., and R.T Muth. 1988. Description and
identification of June, Utah, and mountain sucker
lanae and earh' ju\eniles. Report 88-8. Utah State
Division of Wildlife Resources. 107 pp.

U.S. Fish and Wtldlife Service. 1995. June sucker
(Chasmistes liorus) reco\ei"\' plan. Salt Lake C"it\\
UT 55 pp.

Received 6 October 1997
Accepted 1 7 February 1998

Great Basin Natmalist 5S(4). © 1998, pp. 393-395

FLWEXS, COW BIKDS, AND STAULIXCS AT SPRINGS AND
STOCK TANKS, MOjA\ E NATIONAL PRESERVE, CALIFORNIA

I^ichanl L. Kiiiulit', Kiclianl j. Cainpl, and I Icallirr A.L. Kniglit-
Kcy icords: ('oininoii Raicn. Broun-licadcd ('ouhird. European St(irliii>i. water. Mojare Desert.

W'c iinesti^iited use ol iiatinal and artificial
water sources b\ Common Ravens {Corviifi
cora.x). Hrown-lieaded (^owhirds (Molothnis
(iter), and European Starlin,e;s iStunim vulgaris)
in the Mojave National Preserve, California.
Our stud)' was motivated by earlier observa-
tions of these 3 species in which they were
seen at stock tanks but not detected at springs.
Ra\'ens, cowbirds, and starlings have been
viewed as detrimental to \\11dlife for a variety
of reasons including depredations on endan-
gered species (e.g., desert tortoise [Gopheriis
agassizii] b\' ra\'ens, Boarman 1993), nest para-
sitism of nati\e songbirds by cowbirds (Trail
and Baptista 1993), and competitixe displace-
ment of cavity nesting birds b\ starlings
(Weitzel 1988, Kerpez and Smith 1990).

The Mojave National Preserve, located in
San Bernardino Count); California, comprises
appioximateK 681, ()()() ha. It falls within an area
bounded on the north b\' U.S. Interstate High-
wax 15, the east b\ the Colorado River, the
south by U.S. Interstate Highway 40, and the
west by the convergence of these 2 highways.
The study area consists of mountain ranges
interspersed with basins varying in elevation
from 280 m to 2400 m above sea lexel. The cli-
mate is seasonal and severe, being warm
(>26°C) in summer and cool (<11°C) in win-
ter, with an annual mean temperature of 17 ±
9°C {s). A\erage rainfall is <12 cm for most of
the area, with most precipitation occurring
from December through March (Johnson
1968). Vegetation consists of widely spaced
shrubs, and the major floral communities in-
clude alkali sink, creosote bush (Larrea triden-
tata) scrub, shadscale {Atriplex confertifolia)

scrub, Joshua tree (Yucca hrevifolia) woodland,
and pinyon-juniper {Piniis tnonophijlla-jiiiii-
pcrus spp.) woodland (Munz and Keck 1959).

Between 2 June and 5 JuK 1993, we sam-
pled 60 sites consisting of 20 springs, 20 stock
tanks, and 20 points located away from springs
and stock tanks (controls). Springs, stock tanks,
and control points were chosen from U.S. Geo-
logical Sune\ maps. Control points were posi-
tioned >300 m from a road and >1 km from
stock tanks or springs. All points were >3 km
from human habitation. Stock tanks and springs
all contained open, flowing water. Stock tanks
were metal or concrete structures and aver-
aged 3 m in diameter. Controls, springs, and
stock tanks were located so as to represent as
broad an area as possible within the Mojave
National Preserve, maximize the distance be-
tween sites, and reflect dominant regional
\egetation.

Because our study examined whether bird
species were associated with water, but not
diurnal acti\it\ patterns, we visited sites
throughout da>'light hours. There were no sta-
tistical differences in time of da\' when the 3
site categories (springs, stock tanks, controls)
were ^ isited (Kniskal-W^allis, X" = 3.96, df = 2,
P = 0.14, PROG UNRARIATE, SAS 1987).
We restricted our analyses to bird detections
<50 m from the water points using a fixed-
distance circular-plot method (Re\'nolds et al.
1980). We counted all detections based on
either \isual or aural observations during a 10-
min period and recorded beha\ior (perched,
fUing, singing, feeding, drinking). Obsenation
points were positioned so as to offer clear
views of w^ater sources. Following each count,

'Department of Fishen and Wildlife Biologj. Colorado State Universitj; Fort Collins. CO 80523.
^The Nature Consenancy, 633 S. College, Fort Collins, CO 80524.

393

394

Great Basin Natuflalist

[Volume 58

we sun'e>'ed an area \\ ithin a 5()-iii radius from
the water source (or a designated center point
for control sites) for sign (droppings, tracks,
shells) of wild burros {Eqiiiis asiniis) and
domestic cows. Each site was surveyed only
once.

The total number of individuals seen during
each count was used to compute means (isj)
for each species within each of the 3 site cate-
gories. A G-statistic (PROC FREQ, SAS 1987)
was used to test for independence of species
occurrences at control sites, stock tanks, and
springs.

Ravens, starlings, and cowbirds were not
seen equalh at stock tanks, springs, and control
sites (G = 5.74, df = 2, F = 0.057). Ravens and
starlings were seen only at stock tanks (ravens:
1.00 ± 0.26 [n = 20 individuals at 12 sites]; star-
lings: 0.60 ± 0.41 [n = 12 individuals at 4 sites]).
Brown-headed Cowbirds were seen at stock
tanks (0.45 ± 0.29 [n = 9 individuals; 5 stock
tanks]), were never seen at control sites, and
were detected only once at springs (0. 10 ± 0.07,
[n = 2 individuals]). Of the ravens seen at stock
tanks, all but 4 were seen drinking (80%).
Only 17% (n = 2) of starlings were seen drink-
ing and only 1 cowbird was observed drinking.

Recent evidence of cattle use was obsei'ved
at all stock tanks, at 10 control sites, and at 11
springs. Burro sign was found at half of the
springs, at only 2 stock tanks, and at none of
the control points. One tortoise shell was
found at each of 2 different stock tanks; no tor-
toise shells were found elsewhere.

Ravens are a species native to the Mojave
though evidence suggests their populations
have increased substantially, concurrent v\'ith
human presence associated with linear right-
of-ways, sanitary landfills, and agriculture
(Knight and Kawashima 1993, Knight ct al.
1993). Ravens have been implicated as a
causative factor in the decline of the desert
tortoise, a federally threatened si)ecies (Coal-
man 1993), and shells o( tortoises found at
stock tanks are within the size class suspected
of being consumed by ravens (Boarman 1993).

Brown-headed (>'owl)irds did not historicalK
occur in the east Mojave Desert (l.a\ni()n 1987).
We observed groups of cowbirds, including
individuals copulating, at stock tanks, w Ik rcas
we detected onK 2 cowbirds at a sirring as
they flew past. Clowbirds are stated to bi- asso-
ciated with Ii\ (-stock (\hi\ri('l(l 19(i5, Kotlistcin

et al. 1980). Of the 7 counts at stock tanks when
cows were present, we detected cowbirds onl\'
once. A more detailed stud> is required to doc-
ument the association of cowbirds in Mojave
Desert rangelands with water and lixestock. If
cowbird distribution in the Moja\e Desert is
enhanced by the presence of stock tanks, it
would be worthwhile to investigate what
impacts they are having on desert bird species
(Laymon 1987). In the east Mojave Desert, we
encountered starlings only at stock tanks or in
the vicinity of homes and towns and have yet
to obserxe them at natural water sources or
undistinbed parts of the desert.

When the U.S. Congress passed the Cali-
fornia Desert Protection Act in 1995, it rewTote
the maps of southeastern California. Two na-
tional monuments (Death Willey, Joshua Tree)
were made national parks, and the East Moja\e
National Scenic Area (U.S. Bureau of Land
Management) was made an adniinistrati\ e imit
of the National Park Senice and renamed the
Mojave Nationtil Presene. Artificial water stnic-
tures are allowed in Joshua Tree National Park
and discouraged in Death Valley National
Park; there is not yet a policx' regarding water
in the Mojave National Presene. Historically,
water has been viewed as a limiting factor for
wildlife in much of the desert Southwest. This
belief has led to a \'irtually uncjuestioned belief
that if some water is good for wildlife, then
more water is better (Bro>les 1995). Our stud\
hints at a possibility that there may be unan-
ticij^ated costs associated with water de\ t'lop-
ment which, in turn, may ha\e implications
for desert w ildlife connnunities.

Although our results are based on a single
field season and within only a portion of the
Moja\e Desert, our findings suggest that addi-
tional research on bird connnunities associ-
ated with desert water sources is wairaiited.
.More detaiU'd studies might substanliati'
whether the pattern we [ireseiit is indeed
widespread. In addition, studies that (|nantil\
bird use of difiercnt t\pes ol water, and the
plixsii'aj and NcgetaliNc dillcrenccs associated
with water t\pes, might re\c'al processes that
e.\|ilain ecological patterns obserxed.

We (Icdicalc this papei' (o the late jack
Kawashiiiia, an indix iciual who cared more than
many lor the integrit\ ol the Mojaxc Desert.
Our work was made possible b\ Sonthein (]al-
ilornia Edison and (Colorado State Inixcrsitv

I99.S]

Notes

395

Lin.KATi KK (:rii:i)

B()\H\I\\. W.I. 1993. WluMi a iiativr prt'ilalor hcionics a

pest: a ca.se stuck. Pajies 1(S(S-2()1 /;i S.K. Majmnclar.

E.W. Miller. J.li Pratt. R.p: Schiiialz. and K.K.Bnmn.

editors. Conservation and resource nianagetnciit.

PennsyKania Academy of .Science Press, Hiaston.
BuDVl i:s. B. 1995. Desert wildlife water de\elopnients;

((uestioiiing use in the Southwest. Wildlife Society

Bulletin 23:663-675.
Johnson. .A.W. 1968. The exolution of desert xciietatiou in

western North America. Pages 101-140 in V,.\\.

Brown, editor. Desert hiology. V'ohniu' I. Aiadeniic

Press, New York.
Kr.RPEZ, T.A., AND N.S. Smith. 1990. Competition hitwcen

European Starlings and nati\e woodpeckers lor nest

caxities in saguaros. Auk 107:367-375.
Knh.ht. R.L., .WD J.Y. K,\\\ASHI\IA. 1993. Responses of

raven and Red-tailed Hawk populations to linear

right-of-wa\ s. JoTunal of Wildlife Management 57:

266-271.
Kmcht. R.L.. ll.A.L. Knk;ht, and R.J. Canh^. 1993. Raven

populations and land use patterns in the Mojave

Desert. California. Wildlife Socictv Bulletin 21:

-469-471.
Lavnkxn. S.A. 1987. Brown-headed Cowliirtis in CJalifornia:

historical perspectives and management opportuni-
ties in riparian habitats. Western Birds 18:6.3-70.

\\\\\ II I I). II. f". 1965. rlic Brown-headed Cowliird willi
oiti and new iiosts. Living Bird 4:13-28.

Mlnz, RA., and ]>D. Kl'.ck. 1959. A California flora. Uni-
versity of (California Press, Berkele\.

Rkvnoids. R.T, J.M. Scorr, and R.A. Nussbaum. 1980. A
variable circular-plot method for estimating bird
iiuiuIhts. Condor 82:309-313.

Korii.sn.iN, S.I.. J. \T:hnk. and E. Sti::vi:ns. 1980. Range
expansion and diurnal changes in dispersion of the
Brown-headed (Covvhird in the Sierra Nevada. Auk
97:253-267.

SAS IN.STITLTF., Inc. 1987. SAS/stat guide for personal com-
puters. Version 6 edition. SAS Institute. Inc.. Car>',
NC. 1029 pp.

Tiuil.. PW, AND L.E Bakiista. 1993. The impact of Brown-
headed CCovvbird parasitism on populations of the
Niittall s White-crowned Sparrow, (ionsenation Biol-
og\' 7:309-315.

Weitzel, N.H. 1988. Nest-site competition between the
European Starling and native breeding birds in
northwestern Nev ada. Condor 90:515-517.

Received 13 September 1997
Accepted 26 January 1998

THE

GREAT BASIN

NATURALIST

INDEX

VOLUME 58 — 1998

BRIGHAM YOUNG UNIVERSITY

Great Basin Naturalist 58(4), © 1998, pp. 398-404

INDEX

Volume 58—1998

Author Index

Andersen, W. Ralph, 12
Ashley, Michael C, 289
Austin, Dennis D., 188

Babhel, David G., 12
Ballinger, Royce E., 375
Barnum, Andrew H., 92
Baron, Jill S., 250
Bates, Jon D., 363
Baumann, R.W., 192
Belk, Mark C, 390
Bell, Christopher J., 82
Belthoff, James R., 167
Blank, Robert R., 217
Bleich, Vernon C, 265

Camp, Richard J., 393
Cassidy, Kelly M., 199
Chace, Jameson E, 245
Clark, William H., 295
Conrad, Mark A., 231
Crawford, John A., 344
Cruz, Alexander, 245
Curson, David R., 90

Davis, Frank W, 199
Davison, William B., 285
Delk, Jennifer K., 282
deNoyelles, Erank, Jr., 231
Dewey, Sharon L., 231
Donovan, Michael H, 87
Driese, Kenneth L., 199

Edge, W. Daniel, 344

Flechtner, Valerie R., 295
Fraas, W Wyatt, 28
Erisina, Michael H., 28

Goguen, (.'hristoiihcr B., 90

Hall, Linnea S., 66, 328
Hamlin, Rohin, 328

Harper, Kimball T, 1, 198
Horton, Chris, 292

Jacobi, G.Z., 192
Johansen, Jeffrey R., 295

Kilgore, Maiy Jane, 282
Klennnedson, James O., 352
Knight, Heather A.L., 393
Knight, Richard L., 393
Kondratieff, Boris C, 250
Kuenzi, Amy J., 328
Kiilkdyliioglu, Okan, 380

La Francois, Toben, 250
Lemos-Espinal, Julio A., 375
L\ iin, Snellen, 328

Marcus, W. Andrew, 156
Mathews, Nanc\' E., 90
Maxwell, Bruce, 156
McArthur, E. Durant, 1, 12
Mead, Jim I., 82
Miller, Richard E, 363
Milner, Gaiy, 156
Minshall, G. Waxne, 54
Morrison, Michael L., 66, 76, 328
Mudge, Joann, 12
Murray, Michael 1^ 199

Nealc. jcnnilcrC:.C., 328

Palnuiuist, DebraE., 217
Pennuto, (Christopher M., 231
Powers, Leon R., 167

Hcynolds, iiinolliN 1)., Hi7
Robinson, (ChristoiiiuM- T., 54
Robinson, Megan. 87

Sacks, Bcnjaniin N., 328
Sanderson, Stewart C., 1, 12
Schaner, Andrew J., 273

39S

1998]

Index

399

Schwaner, Teny D., 87
Severson, Kieth E., 312
Shannon, Joseph R, 97, 147
Smith, GcoflivN R., 375
Smith. Robert L., 292
Sowell, John B., 273
Spurrier, Maiuo Frost, 1S4
Stark. Bill P.. 282
Stevens, Lawrence E., 97, I4'i
Stoms, David M., 199
Sublette. James E., 97, 147
Sureda, Maite. 76
S\ ejear. Toin; 363
S\euni, Colin M., 344
Szewczak, Joseph M., 66
Szewczak, Susan M., 66

Ta\loi. Tiniothy J., 265
Tiedemann, Arthur R., 352
Trent, James D., 217

Uresk. Daniel W., 312
Urne.s.s. PhihpJ,. 188

\'an Buren. Renee, 1, 12
V'ertueci. Frank A., 231
\in>ard. Can L.. 380

Wade, Brian K., 273
Wambolt, Carl L., 28
Warfa, Ahmed M, 38
Welsh, Stanley L., 45, 386

Younsj, James A., 217

Key Word Ixdex

Taxa described as new to science in this \ ohmie appear in boldface t\pe in this index.

Abedus herberti. 292
accepter, 90
Aedes dorsalis. 184
age, 390
algae

soil, 295
Allenroljea occidentalis, 217
alliance, 199
allied taxa, 38
altitude variation, 375
Anthemideae, 1
aquatic

chemistrv; 250

insect, 292

in\ertebrates. 250
arid regions. 66
Arizona

Glen Canyon Dam, 97, 147

Grand Canyon, 97. 147
Artemisia, 1, 12
assessment

conservation, 199
Astragolu.s. 45. 386
Astragalus concorditis Welsh,

386
Atriplex lentijonnis spp. torreyi,

217
autopol\ploid\. 12
avifauna. 167

Baja California, Mexico, 295
bats, 66

bioassessment. 54
biodiversity; 147

biogeograph), 147
biomass, 312
bird

abundance, 328

species richness, 328
bisexual form. 380
bison, 245
Bison bison, 245
bitterbrush. 28

Black Hills, [South Dakota], 312
Black-billed Magpies, 289
brood(s), 344

-ing, 292

parasitism, 90, 285
Brown-headed Cowbird, 90,

245, 285, 393
browsing, 28
bud development, 28
Bufo boreas, 87

California, 265

Mojave Desert, 393
Truckee River, 328

camp, 156

Capitol Reef National Park,
[Utah], 250

Cata\ iiia, 295

Cavernocypris subterranea, 380

Central Desert, [Mexico], 295

Centrocerciis urophasianiis, 344

Chasmistes lioriis, 390

Chironomidae, 97, 147

Chiroptera, 6

Cladotanytarsus marki Sub-
lette, 97

collections

winter, 231
Colorado, 245. 273

Gunnison Basin, 273

River, 97, 147
Common Raxen. 393
community, 147

structure, 231
conservation assessment, 199
Contopus sordiduhis, 90
crenobiont. 380
Cricotopus (Cricotopus) hlinni

Sublette, 97
Cricotopus (Cricotopus) herr-

manni Sublette, 97
cr\ptogamic crusts. 295
Cylindrocystis brebissouii \ an

deserti, 295
Cypridopsinae, 380

demography, 375
desert, 66

rock pools, 250
diet

fish. 292
diploid. 12
distribution, 97
disturbance, 156, 250
dixersit)', 363

floristic, 312

ecology, 380
ecoregion, 54
ecotones

forest-meadow, 273

400

eil,g, pivdation. 292
Elakatothrix obtii.sata, 295
eolian dust, 217
epiproct, 282
European Starling, 393
eur\'ecious species, 97
extinction, 82

Fasciculochloris mexicana, 295

Fclis concolor; 265

feral horses, 289

fish diet, 292

floristic di\ ersit), 312

flow regulation, 147

forest-meadow ecotones, 273

functional feeding groups, 231

gap analysis, 199

Glen Canyon Dam, [Arizona],

97,'l47
Grand Canyon, [Arizona], 97

Dam, 147
grazing

livestock, 188
Great Basin, 66
grooming habits, 289
growth, 390
Gunnison Basin, [Colorado], 273

habitat, 54, 66, 344

montane, 231

riparian, 328

use, 76
habits

grooming, 289
herbage yield, 352
hibernation, 66
horses

feral, 289
host-parasite interaction, 285
h\])ridizati()n, 12
nVdracluiidia, 184

Idaho, 54, 380

Idaho National Engineering

and En\ iromnental Labora-
tory (INEEL), 167
insects

stream, 231

June sucker, 390
juniper debris, 363

co\er, 199

luanageiiient, 199
Lcmiitiscits, S2
life hisforN, 390

li/.ard, 375
litter 352
livestock grazing, 188

Great Basin Natl iulist

macroin\ertebrates, 54
management, 156
meadow

subalpine, 273
Mertensia ohlonf^ifnlia, 38
Metriocnemtis stevensi Sub-
lette, 97
Mexican Spotted Owl, 76
Mexico, 295

Baja California, 295

Central Desert, 295
microbiotic crusts, 295
Micrutiis, 82
midges, 97

Mojave Desert, [California], 393
Molothnis (Iter, 90, 245, 285
Montana, 28
montane habitat, 231
moiphologv', 38, 282
mortality, 265
moscjuito parasitism, 184
mountain lion, 265
mule deer, 188, 265

National Vegetation Classifica-
tion S\'stem, 199
nestling growth, 285
Nevada

Truckee River, 328

new

species, 97, 386

taxa, 45
nomenclature, 45, 386
North America

western, 282

Odocoilciis liciniDinis, 265
otoliths, 390

parasitism

moscjuito, 184
park, 273
pliosphorus, 54
Pica j)ic(i, 289
Picea eii<!.cliiuimtii, 273
plant

composition, 352

cover, 352

species, 312
Pleistocene, 82
poKploid, 12
poiidcrosa pine, 312
population

density, 375

size, 87
potential

predator, 87

pre\', 87

[\blume 58

predation, 265

egg 292
prexalence, 184
production, 312
Purshia tridentata, 28

range

expansion, 245

summer, 352
R.\PD, 1, 12
replacement rate, 375
reproduction, 375
riparian habitat, 328
rodents. 76

Sage Grouse, 344
sagebrush

obligates, 167

shrubsteppe, 167
Sarcobafus vennicuhittis. 217
Sceloporiis gramniicu.s. 375
seed germination, 273
seedling establishment, 273
SEM, 282

serial diseontinuit\ ccMicept, 147
shoot growth, 28
small mammals, 76
soil

algae, 295

C, 352

K, 352

moisture, 273

N, 352

P352

S, 352

textiue, 273
South Dakota

Black Hills, 312
species

composition, 363

euiyecious, 97
Spliacrofncria. 1
spotted knapwiTil, 156
stocking le\els, 312
stonuicii contents, 292
stoneflv, 282
stream insects, 231
subalpine meadow. 273
succession, 188

zonal, 363
summer range, 352
sur\ i\ orship, 265, 375
Surlt.sa. 282
synonv niies. 97

rdiKiciliiin. 1

taxononu, 1, 38, 386

tetraploid, 12

ihildsidcs spluiiinoniiiL 184

1998]

Index

401

trail , 156

Tridcntatac, 12

Truckee River [California/

Nevada], 328
t\ pification, 38

iiiitUTston. 312

patterns, 363
Utah, 76, 250

Capitol Reef National Park.
250

Utah Lake. 390

vegetation
change, 188
t>'pe, 328
zones, 66

Washington, 344
water, 393

mites, 184

source, 66
western

juniper, 363

North America, 282

Wood-Pewee, 90

wilderness, 156
winter collections, 231
Wyoming, 231

>ield

herbage, 352

zonal succession, 363

402 Great Basin Natl ii\LiST [Volume 58

TABLE OF CONTENTS

Volume 58

No. 1— January 1998
Articles

Tiixononix of Splwcromcrid, Aiicinisia, and Tanacetum (Compositae, Anthemideae) based on randoniK'

amplified poK nioiphic DNA (RAPD) E. Durant McArthur, Renee Van Buren,

Stewart C. Sanderson, and Kimball T. Harper 1

RandoniK amplified poKmorphic DNA analysis (RAPD) of Artemisia subgenus Tridcntatae species

and hxbrids E. Durant McArthur, Joann Mudge, Renee Van Buren, W. Ralph Andersen.

Stewart C. Sanderson, and David G. Babbel 1 2

Bitterbiiish (Piirshia tridentata Pursh) growth in relation to browsing Carl L. W'amlioit,

VV. Wyatt Fraas, and Michael R. Frisina 28

Identity of Mertensia ohlongifolia (Nutt.) G. Don (Boraginaceae) and its allies in western North

America Ahmed M. W'arta 38

Astragalus (Leguminosae): nomenclatural proposals and new taxa Stanlex' L. Welsh 45

Regional assessment of wadable streams in Idaho, USA Christopher T. Robinson

and G. Wayne Minshall

Bats of the White and Inyo Mountains of California-Nevada Joseph M. Szewczak,

Susan M. Szewczak, Michael L. Morrison, and Linnea S. Hall

Habitat use by small mammals in southeastern Utah, with reference to Mexican Spotted Owl man-
agement Maite Sureda and Michael L. Morrison

Late Pleistocene microtine rodents from Snake Creek Burial Cave, White Pine Count); Nexada ....
Christopher J. Bell and Jim I. Mead

Notes

Western toad, Biifo hnreas, in southern Utah: notes on a single population along the East Fork of the

Sevier River Megan Robinson, Michael P Donoxan, and Teriy D. Schwaner 87

Western Wood-Pewees accept cowbird eggs David R. Curson, C-hristopher B. Goguen.

and Nanc\ E. Nhithews 90

Book Review

Few and far bet\veen: moments in the North American DesiMl John Martin Cantphcll

.Andrew 1 1 . lianunn 92

No. 2— April 1998
Articles

Chironomidae (Diptera) of the C'olorado River, Grand Canyon, Arizona, USA, I: s\stematics and
ecology James K. Sublette, Lawrence E. Stevens, and Joseph P Shannon

Chironomidae (Diptera) of the Ciolonido liixcr, (irand Canxon, .Xii/ona, I S A, II: factors inllncncing
distribution Lawrence E. Ste\ens, James E. Sublette, and Josepii I! Shannon

Spotted knapweed distribution in stock camps and trails of the Si'lwax-Bitlciroot \\ ildiriuss
\\. .Viidrcw \larciis, ( iaiv MiiiuT, and Brncc Maxwell

1998] Index 403

Brcc'diiiU i)ircls at the Iclalio National Ijiiiiiu'criuii and l'",n\ ironincntal Lahoraton, 1985-1991

James R. BcltlioH, I. con W. I'owcrs, and I'iniothy D. Reynolds 167

Mite parasitism of mosciuitoes in central Wyoming Margo Frost Spurrier 184

Vegetal change on a northern Utah foothill range in the absence of Ii\'estock grazing between 1948

and 1982 Dennis D. Anstin and I'hiHp j. I'nicss 1 88

Obituary

ArdiMi R. (iaulin, 191 1-1997: obituan ami Hst ol pul)lications R.W. Baninann

andC.Z. Jacobi 192

Book Review

Wild plants and nati\e peoples of the Four Comers WiUiani W. Duutuirc and Gail D. Tienieij

Kimball T. Harper 1 98

No. 3— July 1998

Articles

Gap anaKsis of the vegetation of the Intemiountain Semi-Desert ecoregion David M. Stoms,

Frank W. Davis, Kenneth L. Driese, Kelly M. Cassidy, and Michael E Murra\ 199

Natural histon of a saline mound ecosystem Robert R. Blank, James A. Young,

James D. Trent, and Debra E. Palmquist 217

Winter macroin\ertebrate communities in two montane Wyoming streams

Christopher M. Pennuto, Frank deNoyelles, Jr. Mark A. Conrad, Frank A. Vertucci,

and Sharon L. Dewey 231

Range of the Brown-headed Cowbird in Colorado: past and present Jameson F Chace

and Alexander Cruz 245

Chemical and biological characteristics of desert rock pools in intermittent streams of Capitol Reef

National Park, Utah Jill S. Baron, Toben LaFrancois, and Boris C. KondratiefT 250

Sur\ivorship and cause-specific mortalit\ in fi\e populations of mule deer \ernon C. Bleich

and Timoth\' J. Taylor 265

Persistence of subalpine forest-meadow ecotones in the Gunnison Basin, Colorado

Andrew J. Schauer, Brian K. Wade, and John B. Sow t'll 273

Comparison of the epiproct structure of two closeh' related species, Sweltsa fide lis (Banks) and .S.

revelstoka (Jewett) (Plecoptera: Chloroperlidae) Jennifer K. Delk, Mar\' Jane Kilgore,

and Bill P Stark 282

Notes

Star\ation and nestling ejection as sources of mortalit}- in parasitized Lazuli Bunting nests

William B. Davison 285

Observations of Black-billed Magpies (Pica pica) grooming feral horses {Equus cahallus)

Michael C. Ashle> 289

Fish predation on giant water bug (Heteroptera: Belostomatidae) eggs in an Arizona stream

Robert L. Smith and Chris Horton 292

404 Great Basin Naturalist [\bhinie 58

No. 4— October 1998
Articles

Algal coinpositioii of'miciohiotic crusts from the Central Desert of'Baja California, Mexico

Valerie R. Flechtner, Jeffre\' R. Johansen, and William H. Clark 295

Response of underston- species to changes in ponderosa pine stocking levels in the Black Hills . . .

Daniel W. Uresk and Kieth E. Severson 312

Bird use of riparian \egetation along the Tmckee River, California and Nevada Snellen L\nn.

Michael L. Morrison, Am>' J. Kuenzi, Jennifer C.C. Neale, Benjamin N. Sacks.

Robin Hamlin, and Linnea S. Hall 328

Use and selection of brood-rearing habitat by Sage Grouse in south central Washington

Colin M. Sveum, John A. Crawford, and W. Daniel Edge 344

Soil-\egetation relations of recovering subalpine range of the Wasatch Plateau

James O. Klemmedson and Arthur R. Tiedemann 352

Underston- patterns in cut western juniper (Jwiipenis occUlcntalis spp. occidentalis Hook.) wood-
lands Jon D. Bates, Richard E Miller, and Ton\ Sxejcar 363

Comparati\e demography of the high-altitude lizard, Sccloporus p-(nnmicus (Phrynosomatidae), on

the Iztaccihuatl Volcano, Puebla, Me.xico Julio A. Lemos-Espinal, Royce E. Ballinger

and Geoffrex' R. Smith 375

New bisexual form of Cavcniocypris suhterranea (Wolf, 1920) (Crustacea, Ostracoda) from Idaho

Okan Kiilkoyliioglu and Can' L. Vinxard 380

An undescribed As^raga/w.S' (Leguminosae) from southern Utah, a new subsection of the genus, and

validation of the combination Sphaeralcea janeae (Welsh) Welsh Stanley L. Welsh 386

Notes

Age and growth of June sucker iChasmistes lionis) from otoliths Nhirk C. Belk 390

Ravens, cowbirds, and starlings at springs and stock tanks, Moja\ e National Presen e, California . . .

Richard L. Knight, Richard J. Camp, and Heather A.L. Knight 393

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(ISSN 001 7-3614)

GREAT BASIN NATURALIST voss no 4 October 1993

CONTENTS

Articles

Algal composition of microbiotic crusts from the Central Desert of Baja California,

Mexico .... Valerie R. Flechtner, Jeffrey R. Johansen, and William H. Clark 295

Response of understory species to changes in ponderosa pine stocking levels in

the Black Hills Daniel W. Uresk and Kieth E. Severson 312

Bird use of riparian vegetation along the Truckee River, California and Nevada
. . . Snellen Lynn, Michael L. Morrison, Amy J. Kuenzi, Jennifer C.C. Neale,

Benjamin N. Sacks, Robin Hamlin, and Linnea S. Hall 328

Use and selection of brood-rearing habitat by Sage Grouse in south central Wash-
ington Colin M. Sveum, John A. Crawford, and W. Daniel Edge 344

Soil-vegetation relations of recovering subalpine range of the Wasatch Plateau . .

James O. Klemmedson and Arthur R. Tiedemann 352

Understor)' patterns in cut western juniper (Juniperus occidentalis spp. occiden-

talis Hook.) woodlands. . . . Jon D. Bates, Richard E Miller, and Tony Svejcar 363

Comparative demography of the high-altitude lizard, Sceloporus grammicus

(Phrynosomatidae), on the Iztaccihuatl Volcano, Puebla, Mexico

Julio A. Lemos-Espinal, Royce E. Ballinger, and Geoffrey R. Smith 375

New bisexual form of Cavemocypris subterranea (Wolf, 1920) (Crustacea, Ostra-

coda) from Idaho Okan Kiilkoyliioglu and Gary L. Vinyard 380

An undescribed Astragalus (Leguminosae) from southern Utah, a new subsection
of the genus, and validation of the combination Sphaeralcea janeae (Welsh)
Welsh Stanley L. Welsh 386

Notes

Age and growth of June sucker {Chasmistes lionis) from otoliths . . . Mark C. Belk 390

Ravens, cowbirds, and starlings at springs and stock tanks, Mojave National Pre-
serve, California Richard L. Knight, Richard J. Camp,

and Heather A.L. Knight 393

Index to Volume 58 397

nil II II III I

2044 072 23